Rob's Idaho Perspective

Impressive Tranformation of Study Area Snowpack

2012-01-26T07:47:00.000-07:00

I have been accused on occasion of being a data geek. This post should help substantiate that accusation!

For those who tracked my goshawk research last year, you may remember that the late spring snows caused significant difficulties in our field work. So much so that this year I am proposing to start the field season one week later and have even considered starting two weeks later! Then the very dry winter hit. The snow pack in my study area was less than half of normal. This caused concern on the other end of the spectrum - should I start the season earlier?

There is not much I can do about it yet, but that didn't stop me from keeping a close eye on the numbers. As many have heard, and others have witnessed directly, there have been some pretty impressive storms in the northwest. The graph below illustrates the 2011 snow pack, which was near normal, and this year's snow pack. Check out the impact of those recent storms!

Magic Mountain SnoTel data.

January snow in not a strong predictor of snow pack in May, so I will just have to wait. Regardless, I will continue to keep a close eye on the matter.

Flying Paint and Flying Birds

2012-01-21T18:06:00.000-07:00

Back in September for International Vulture Awareness day, Karyn volunteered at the Peregrine Fund's World Center for the Birds of Prey. She volunteered to lead a kid's painting of a California Condor. She signed me up as her dutiful assistant (summary of the event can be found here). Apparently we did a good enough job as they contacted us again for a repeat. Today was our day to be back out in front of 50 to 100 kids, trying to manage the chaos. Somehow we survived... I think...

First painting completed today - Two California Condors.

There were quite a few more families that came through today than last September. In addition, the average age of our guest artists was significantly lower than last fall. Regardless, they were very successful in completing a new painting today and completing one that was just started last time. The work is spectacular considering the average age of the guest artists was significantly less than ten years old.

First paint on the canvas!

As with the last time we did this, Karyn had sketched the design onto a blank canvas. Actually, this was one she had prepared for last September, that we didn't quite get to.

Early contributors.

We were busy right from the start. Just minutes after opening, while we were still trying to get set up, paint was flying on the canvas. The event was a family day and had been promoted broadly. A local radio station was onsite as were food vendors. The admission was free as well. Anyway, the crowds didn't let up all day long.

Instruction from Karyn.

We had a photograph that the painting was based on and Karyn had painted a small rendition herself to help the young artists extrapolate from a highly detailed picture down to a handful of paint colors. My job was to replace the water in the trays, clean the brushes, provide crowd management, and occasionally provide some basic painting tasks to the artists. Some parents left the management up to us, while others jumped in to lend a hand or offer encouragement.

Friendly assistance.

The detail is starting to show!

Final touches!

First painting completed today.

With the first painting complete, we returned to the second painting that was started back in September but not finished. This painting was of two Rüppell's Vultures from Kenya.

Great progress on painting #2!

Finishing touches.

Completed painting #2

It was a big day and both Karyn and I are exhausted. However, the investment was well worth the effort. Exposing this many families to the world of wild birds is outstanding. Watching young people take a true interest in raptors is priceless. This should definitely help with the mission of the Peregrine Fund. We are happy that in our own small way we can contribute to their very successful programs of conservation.

The completed paintings are on display at the Peregrine Fund's World Center for Birds of Prey.

Integrating Detection Probabilities

2012-01-20T16:35:00.000-07:00

I guess it has been over a month since I have provided an update on my Goshawk research. That doesn't mean that progress isn't being made. In fact, quite the contrary is true. For those new here, I study breeding season diet and prey abundance influences on the Northern Goshawk in a small isolated forest in southern Idaho. By choosing this filter, you will see all of my previous posts on the first year of my study (stories, photos, videos, etc.). I am now preparing for my second field season this coming May.

In December I finished and submitted my annual report to the Forest Service. This was a major accomplishment and its great to have that behind me. As I mentioned in my previous post I have been studying Hierarchical Bayesian Statistics on my own to rework my analysis to account for detection probabilities and to deal with underlying variance in my prey abundance estimates. This has been a hard path to take. After trying to force my way through it, I have decided to step back and work through a textbook end-to-end including all of the exercises. This is intended to increase my overall confidence in the method and ensure I can adequately explain it in my thesis. The textbook I have chosen is Doing Bayesian Data Analysis: A Tutorial with R and BUGS. Don't the puppies on the cover make it look easy!?! I am now on chapter five and I can honestly saw that this is an excellent book. Even though I have a math degree, it has indeed been over 24 years since I have used calculus. This book is written in relatively easy to understand english with just the right amount of math mixed in.

While working on that exercise, I have continued to apply the concepts to my data analysis. I have made significant progress on this front, however I won't know how correct my analysis is until later. Regardless, I have decided to explain what I have done and what the PRELIMINARY results look like. This will provide a basis for asking the experts to take a look over my work and provide me feedback.

I summarized the first step of this Bayesian re-analysis in a previous post. Essentially the first step was to perform the same analysis which I previously completed using Logistic Regression, but this time using Bayesian approaches. I was successful in accomplishing this task. The results continued to show that avian prey abundance and mammalian prey abundance were important predictors of nest occupancy, but only avian abundance was significant. However, the model including both avian and mammalian prey abundance still fit the data better than the model with only avian prey abundance included. This is why I can say that mammalian abundance was important even though it was not significant.

So the next major step in the analysis, and one of the reasons I am shifting to Bayesian statistics is to include detection probabilities to deal with the issue of false negatives. Essentially the analysis up to this point has assumed that if I found a goshawk on a nest then that territory was occupied - safe assumption - but if I did not find a goshawk then the site was not occupied - a very unsafe assumption. By integrating the probability of detecting an occupied nest into the analysis, I am essentially allowing each of those "unoccupied" territories to instead be "possibly occupied, but not detected". The really cool part is that you can actually do this, through some really fancy calculus. The inclusion of detection probability can have a dramatic impact on the results. It has been shown to have a huge impact on abundance measurements, but my study is not looking into abundance. However, it is still applicable to my study and could strengthen or dilute the effect of predictor variables such as avian or mammalian prey abundance.

Detection probability is usually determined from intrinsic factors in the data. Ideally surveys would be repeated up to three times. These repeat visits provide a basis for the imperfect detection when the animal is detected on one visit, but not another. However, repeat visits are very expensive. Last season we had over 450 survey points. We lacked the time or money to perform repeat visits. My approach to address this took two steps. First, there were two nests where we had broadcast a goshawk alarm call within 200m of the nest and did not receive a response. We later discovered the nest. In these cases I have counted the first visit as no detection and the second visit as a detection. I set all other second visits to NA (no second visit performed). Here is a sample of what the observation table might look like.

Nest	Visit 1	Visit 2
...	...	...
Nest 13	1	NA
Nest 14	0	1
Nest 15	1	NA
Nest 16	0	NA
...	...	...

The Bayesian approach is robust to unbalanced sampling designs such as this. In addition to this minimal data from my surveys, my Bayesian models specify "prior" knowledge of detection probabilities. One of the strengths and one of the criticisms of the Bayesian approach is that you can include "prior" knowledge that influences the results. Those who use frequentist statistics often use this argument against Bayesian results. However, the frequentist approach does have "prior" knowledge built into the assumptions which in most ecological studies, are not fully met!

I know of three other goshawks studies using the same search protocol that I used (it's a Forest Service standard). These studies have found the detection probabilities to be 0.54, 0.75, and 0.90 for single visit surveys. I included in my model the "prior" knowledge that the detection probability was uniformly distributed between 0.5 and 0.9. In other words, it has an equal chance of being any value between 0.5 and 0.9. With this "prior" knowledge and my limited repeat visit datapoints, I should get a new estimate of the detection probability for my study and an estimate of what we actually missed.

First, it is time to perform model selection. Running all of the models that I previously used in Logistics Regression, but this time in a Bayesian analysis, the top rated model was the model including avian prey abundance but not mammalian prey abundance or the percent of the territory which is forested. So, detection probability did have an impact on model selection! Looking into the model results, avian prey abundance remained a significant predictor of nest occupancy (Figure 1). Significance is indicated by the 95% High Density Interval (HDI) not overlapping zero. The High Density Interval is roughly analogous to the frequentist 95% confidence interval.

Figure 1: Posterior distribution of model coefficient for avian prey abundance.

The combination of the "prior" for probability detection and my data produce a posterior estimate for the probability of detection for my survey of 67.8% (Figure 2).

Figure 2: Posterior distribution for Probability of Detection.

The real unique result comes from the estimate of how many occupied nests there really were. The sampling approach used to solve these problems essentially produced 50,000 estimates of all of the possible values, each constrained by the model and the priors. The result is a distribution of those estimates which provide a credible probability of the true value given the priors and the data. Figure 3 illustrates the estimated number of occupied territories out of the original set of 24 historical goshawk territories. Hence there is a 95% chance that there were 11 to 16 occupied territories out of 24. The expected value is 12 nests (mode) or 13 nests (mean). The "observed" value, those that we actually found, was 10. The model predicts that we most likely missed three occupied territories. Had you asked me prior to this analysis, I would have guessed that we missed two. I am not surprised that it could be as high as six.

Figure 3: Posterior distribution of estimated occupied nests within 24 historical territories.

Now it's back to the textbook to improve my comprehension and confidence with all that I have explained here. The next step with this analysis will be to integrate the uncertainty of my prey abundance estimates into this model.

Writing this post has helped me clarify which concepts I fully grasp and which still need some work. If you are still reading, thanks for sticking around, I appreciate it. Be sure to let me know if you have any feedback.

More Rarities

2012-01-15T05:44:00.000-07:00

While not as rare as a dark-morph Northern Harrier, I have seen a number of rare birds so far this year. The birds may not be rare for the area in general, but are rare this time of year. The result is that ebird, the bird logging system used across the country, flags the entry as unusual. As a user you have to confirm the observation with an extra step to help insure the entry was not an accident. For example, I have seen Loggerhead Shrikes on three occasions since January 1st (one was probably a duplicate). In each case I have to confirm with ebird that I truly saw a Loggerhead Shrike.

Loggerhead Shrike, rare bird in Idaho for January.

If the bird is considered very rare, then the local ebird monitor will put your entry on hold until additional documentation via a rare bird report is submitted and approved by a reviewing committee. This is all to help preserve the quality of the large ebird dataset.
During the Bruneau Idaho Christmas Bird Count in early January, seven of the species on my list required extra confirmation and two required further documentation. Unfortunately for one of those observations, a Northern Mockingbird, I only had fleeting views. I was trusting two other people in my group that they had great views. While I was reasonably sure from my view it was a Northern Mockingbird, I was not solid enough to complete a rare bird report, explaining each of the field marks in detail.
On Saturday Karyn and I returned to the scene of the crime. There, before us in the same tree, was the Northern Mockingbird. This time I will submit another ebird checklist, get flagged, and confidently submit the documentation AND photos.

Northern Mockingbird in Idaho IN JANUARY!

Northern Mockingbird

To the bird's credit, it is perched above a warm spring, which I sure tempers the cold weather.

The Dark Ghost

2012-01-14T07:22:00.001-07:00

The following is a guest post I wrote for The Nemesis Bird. I am cross posting it here for those who do not read the Nemesis Bird, although you should! The Nemesis Bird is maintained by bird fanatics and researchers and is one of the top birding blogs on the net.

As many birders can attest, species identification can be very challenging at times. The challenge arises from the similarity of many related and sometimes not so related species. Complicating this is the ephemeral nature of birds in general. The dominant feature which makes them so intriguing - the ability to fly - helps them maintain their distance from would be predators and admirers alike. A bird in nature seldom presents itself to a viewer in a fashion presented in most field guides. But, sometimes they do...

Rough-legged Hawk. Snake River Birds of Prey NCA.

Increasing the challenge of identification is the seasonal and regional differences in plumage within the same species. Plumage coloration is also related to the condition of the bird. In many songbirds for example, it has been shown that the coloration can be an honest signal of fitness. The greater the color richness and vibrancy of the adults within a species, the better the body condition, the stronger the immune system, and the higher the reproductive success. While raptors generally have more neutral coloration, there is evidence that the expression of certain pigments correlates with the strength of the immune system. Consider the expression of the color red in the tail of a Red-tailed Hawk or American Kestrel. This red color is believed to be directly correlated to immune system function. This connection is currently being investigated by another raptor biology student at Boise State University - Chris Porterfield.

American Kestrel interacting with Red-tailed Hawk. Idaho.

Bird identification can also be challenging when a species presents itself in different color-morphs. As a raptor biologist this is a central issue in my field. Most raptor species present different color morphs, sometimes as many as three or four. These color morphs are not to be considered sub-species unless individuals of a given color morph begin to assortatively mate - mate only with other individuals with that color morph - and they evolve away from the central population. Color morphs are controlled by genetic factors and thus their prevalence within a population is related to the reproductive success of the individuals carrying the morph. If the morph increases reproductive success then you would expect a greater percentage of individuals in the population to carry the morph or vice-versa. There is some evidence that color morphs have little influence on reproductive success, but the relative rarity of dark morphs leads me to believe otherwise. The morphs are produced by an increase or decrease in the gene expression of melanin - the dark pigment producing the color of most raptors. Dark-morphs are sometimes called melanistic birds. Dark-morph raptors are much more common in the old world than the new world and are more common in some species than others, but it is not understood why.

The story of the ghost

Last week I was helping another graduate student with his field work. Neil Paprocki's project involves winter surveys of raptors within the Morley Nelson Snake River Birds of Prey National Conservation Are a (NCA). Last Monday Neil and I, along with another biologist Liz Urban, were surveying for raptors via a road survey south of Boise. The term "road" is very generous. This 4-wheel-drive path, mostly buried in Russian Thistle tumbleweeds, traverses the western portion of the NCA. We observed Red-tailed Hawks, Rough-legged Hawks, Golden Eagles, American Kestrels, Prairie Falcons, and Northern Harriers. Toward the end of the survey we flushed a bird just ten feet from the edge of the "road". "What was that?!?"

First glimpse of the ghost!

It's a harrier! No! Is it? What? Confusion took over as our brains shuffled the various field marks and signs we use for identification. We kept coming back to Harrier, but then the issue - all Harriers have a wide robust white rump patch easily seen from almost every angle. However, this one did not... The bird flew a short distance before landing out of sight in the sage. We discussed if it was worth flushing this bird again for an identification. In general we try to minimize our disturbance. However, this bird was notable enough and our identification was not positive enough that we decided we were justified to get one more look.

"Normal" Northern Harrier with white rump patch. Roswell, Idaho.

Neil and I exited the truck and started hiking through the sagebrush and grass landscape that makes up the NCA. The bird flushed again. Dang! My camera wouldn't focus... Then I got the shots! In all manner of flight style, shape, behavior, and habitat, this was a harrier. However, there was no white tail band... Do dark-morph harriers exist? None of us had ever seen or heard of one. This is clearly an unusual bird.

Dark-morph Northern Harrier.

Or is it?

Hmm.

Yes it is!

According to various reports (see citations below) only three dark morph Northern Harriers have ever been reported and only one has ever been photographed (Liguori 2009). Dark morphs have been well documented in Northern Harrier's closest relatives, a number of other harrier species in Europe.
This was a fantastic find and an exciting topic to explore. The photos are being shared with the top raptor experts in the country for their expert analysis. Neil returned to the area the next day but was unable to relocate the raptor.
Literature Cited:

Liguori, J. 2009. Distant Raptors. Birding 41:74-76.

Olson, C.V. and S.A.H. Osborn. 2000. First North American Record of a Melanistic Female Northern Harrier. Journal of Raptor Research 34:58-59.

Paprocki, N. 2012. Do Dark Northern Harriers Exist? Wild Lens Blog. Retrieved January 13, 2012 - http://www.wildlensinc.org/blog/

NOGO Mojo!

2012-01-03T10:32:00.001-07:00

Bird geeks around the world recognize the 4 letters "NOGO" as the ornithology code for the Northern Goshawk. Most 4 letter codes consist of the first two letters of the first name followed by the first two letters of the last name as in NOGO for NOrthern GOshawk. Of course, it gets more complicated when two birds would result in the same code. For example, NOrthern SHoveler and NOrthern SHrike. In this case you just have to know that Northern Shoveler is NOSH and Northern Shrike is NSHR, but I degress. This story is about my mojo for finding Northern Goshawks on Christmas Bird Counts! While my sample size is quite small and would not pass statistical evaluation, I can say that I was 100% in finding NOGOs on the two Christmas Bird Counts that I worked on this year (If you don't know, the Northern Goshawk is the study species for my master's program in Raptor Biology at Boise State University).

The Audubon Society has coordinated a count of wintering bird across North America known as the Christmas Bird Count (CBC). These counts use citizen volunteers to count birds in an organized fashion within per-determined 15 mile diameter "count circles". The counts have been performed each year for more than 100 years. The result is one of the most valuable datasets in ecological research. I participated in two counts this year, the Boise CBC centered on the Idaho state capital and the Bruneau CBC centered on CJ Strike reservoir. The counts are a great way to get out and see birds, learn from more experienced birders, meet new people, contribute to that ever important dataset and most importantly of all, contribute to the conservation of these miraculous flighted species.

Great Horned Owl - 1 of 5 I counted on Bruneau Idaho CBC.

The Boise Idaho CBC was held on December 18th. We met early in the morning to split up the territory into separate teams and then further split up the teams into sub-teams. Due to a previous commitment I was only able to volunteer for a half day. Karyn and I, along with another graduate student, Jessie, chose a hiking trail near my house which appeared to not be covered. The days was clear and sunny.

The first part of our loop climbed through a small drainage rimmed with houses where adult and juvenile goshawks have recently been seen. As we walked up the hill, Jessie mentioned that she had never seen a goshawk in the wild. I responded, "like that adult flying up the canyon!" Awesome. The goshawk flew by at eye level before perching in a tree above a house. We were about 50 meters away as it launched off the perch, passed about 20 meters away and bombed toward some Mourning Doves. Unfortunately it came up empty. What a fantastic start to the day - summoning goshawks on demand!!

Rough-legged Hawk. 1 of 3 I observed on Bruneau Idaho CBC.

We continued our hike over the ridge and into the next drainage, where lo and behold, we would find another goshawk, this one a juvenile. These two would be the only goshawks counted during the Boise CBC. Great Horned Owls, Lesser Goldfinches, and a Hairy Woodpecker were other great finds. The three of us ended our half day with 23 species. The total for the Boise CBC effort included 48 volunteers recording 81 species. This was a great result, likely amplified by the great weather (it rained hard last year!).

Next up, on January 2nd, was the Bruneau Idaho CBC. This event is hailed as one of the most fun in Idaho due to its scale. The count is centered on a large reservoir which in winter is home to a mind-boggling number of water birds. Have you ever wondered what 25,000 Mallards looks like? Thousands of Common Goldeneye? Simply amazing! I joined up with other Idaho Bird Observatory bird nerds Jay, Heidi, and Jessica, for a fantastic outing and a number of rare birds.

Small portion of the 25,000 Mallards circling.

First up was our portion of the reservoir. Yes, 25,000 mallards! Mixed in were Northern Pintails, American Wigeons, Red-breasted Mergansers, Common Mergansers, Canada Goose, Snow Goose, and Common Goldeneye. Twelve Bald Eagles stood on the ice watching the melee. As our presence was significantly annoying the local duck hunters we moved on into the woods. The reservoir is lined with Russian Olive groves. As we walked through the groves we found 3 Barn Owls, 3 Great Horned Owls, Ruby-crowned Kinglets, Yellow-rumped Warblers, Dark-eyed Juncos, California Quail, and an unbelievable number of Northern Flickers, etc.

Next up we focused on the farming roads through the southern desert area. This wide open area is pocked with warm springs which attract unique birds. A local fish hatchery brought in the herons - 25 Great Blue Herons in the field next door. Two Loggerhead Shrikes graced our presence. They are much more rare this time of year than their relative, the Northern Shrike. The species list and the counts just kept growing.

Loggerhead Shrike - Rare this time of year.

A local hot spring ditch, very unremarkable looking, provided some of the best treats of the day. Two and maybe three Virginia Rails, Belted Kingfisher, Wilson's Snipe, Lincoln Sparrow, Spotted Towhee, and a Northern Mockingbird! Outstanding. The Lincolns and the Mockingbird are rare enough this time of year that ebird, the bird observation recording system, requires species documentation (as did the Shrike and a handful of other birds we logged!).

Angry Virgina Rail.

Virgina Rail.

Next up - Blackbirds and lots of them. Over 3000 in fact. The huge flock consisting of mostly Red-winged Blackbirds was moving between trees and a recently mowed cornfield. Mixed with the Red-wings were Yellow-headed Blackbirds(rare), Brewer's Blackbirds, Brown-headed Cowbirds(rare), and the not so rare European Starling. Watching the flock were a Cooper Hawk, a Prairie Falcon, a Red-tailed Hawk, and a Rough-legged Hawk. We watched as the Prairie Falcon stooped on the flock, but unfortunately came up empty. Yes, I usually root for the predator. I am an Raptor Biologist after all! We were too close to capture the whole scene in one shot.

Portion of 3000+ flock of blackbirds.

We finished our daylight hiking through more Russian Olives. Expectedly many of the same species were found and counted, but a few new ones were in this area. The raptors were out and hunting - Sharp-shinned Hawks, Coopers Hawks, American Kestrels, AND there in front of me was a juvenile Northern Goshawk! The mojo continued! My day was complete! Not to be outdone, Heidi found a Swamp Sparrow nearby. Unfortunately I did not get to see it. It would have been a lifer. Oh well. I guess I will have to keep birding!

As the final light of the day faded I counted 1100 more blackbirds flying over in groups of 30-50 each. In the distance I could see the 25,000 Mallards taking flight as tens of thousands of Common Goldeneye returned to the reservoir for the night. Wow, Wow, Wow! Pretty cool stuff.

The Bruneau count concludes with a meet up and summary at a local restaurant. The 30 or so volunteers took over the whole place. The staff fed us family style dinner and dessert. It was fantastic as we all shared our stories of adventure and rare birds. Our group of 4 checked in with 64 species. The preliminary total count included 91 species. My only life bird of the day was a Glaucous-winged Gull which was not in our count section but was still a great rare find. I will definitely be back for this count next year!

Wilson's Snipe.

Holiday Birdwatching

2012-01-03T08:48:00.001-07:00

The holiday season concluded a very busy year. In December I wrapped up my final exams and submitted the annual report for my research to the forest service. Both events were quite successful. Shortly thereafter my mother visited for five days.

The primary activity filling our days involved bird watching. The first day I took her out roadside raptor banding. We caught, banded, and released four American Kestrels. A great combination of juvenile and adult, males and females. It was a great day. Unfortunately I was so caught up in the action that I failed to take any photos!

The remaining days of my mother's visit involved visiting a number of the local birding hotspots. Below is a collection of some of my better photos from that week.

Bald Eagle along Boise River.

Great Blue Heron.

Hooded Mergansers.

Male Downy Woodpecker.

Song Sparrow already singing for Spring!

My "prior" brain has become Bayesian "posterior" mush

2011-12-08T16:33:00.000-07:00

Wow, the months sure fly by. It seems like only days ago that I was trapping raptors during fall migration and performing my initial analysis on my goshawk season data. However, I have been very busy and have accomplished a great deal.
The most significant chunk of my time has been devoted to my research annual report. My agreement with the Forest Service requires me to submit an annual report of my study findings. Back in September, I provided a short report which included the status of our nest searches and general goshawk productivity, but much of the analysis came afterwards. By the end of the year I will submit a full report of my results. Before completing the report, I had to watch 3 months worth of nest camera footage and catalog all of the prey items. That was a pretty big time investment. Then came performing the statistical analysis and writing the report. While I could submit a report that just addresses the key questions the Forest Service is interested it, I chose instead to provide a complete report of all the work we performed which includes their key questions as well as the core and secondary questions of my thesis. Additionally, I had the option to submit the results in a general report format, but I chose instead to structure it as a full scientific paper or thesis. This work up-front will greatly streamline my effort when I get around to writing my thesis after my second field season. As a result, it took a lot of time to prepare. I am happy to say that I have submitted a draft to the Forest Service for their review and am awaiting the feedback. In total the document weighs in at 61 single spaced pages! However, I do include lots of photos and detailed maps of each goshawk territory.
The next chunk of my time has been working to figure out Hierarchical Bayesian Analysis. This has been a real challenge. It is not just learning a new statistical procedure, but instead requires a whole new philosophy and approach. As with many tools, the challenge isn't so much in learning the general concepts, but how to apply those general concepts to real problems you are trying to solve. Then, once you have solved the real problem, how do you know it's right? There is no one looking over my shoulder to point out the mistakes. They will all read my report expecting me to be the expert and to educate them. I still have a ways to go...
I am pursuing Hierarchical Bayesian Analysis to address two primary issues I have in my project structure that somewhat violate the assumptions of the frequentist procedures I have used so far. Not to get too alarmed, many papers have been published with these issues, but the right approach is to address them head on. In fact, most published papers have these issues, and only a few recent papers have addressed them. The first significant issue is that I classified historical goshawk territories as "occupied" or "not-occupied" dependent upon whether our search found goshawks nesting there. Of course, if we found a goshawk sitting on a nest, that is an absolute observation. But what about the territories where we did not find goshawks? I cannot say with the same certainty that they were not breeding there. In fact, my procedures have been shown by others to only be 70-90% effective at detecting nesting goshawks. The result is that I am reasonably confident that we missed occupied goshawk nests. Some may even have failed and were abandoned before we entered the field. Yet, they should be classified as occupied if nesting was initiated this season. Bayesian analysis will help me include the detection probability - or the probability that there are "false negatives" in my data.
The second issue is that I am using statistical procedures to produce an estimate of prey abundance in each goshawk territory. While the procedures provide a maximum likelihood value for prey abundance, the values have very wide confidence intervals. They are much more variable than point measurements. The frequentist model fitting procedures I have been using these values in assume a higher precision than this and also assume the error values are roughly normally distributed. These are weak assumptions at best. Those that use these procedures point out that the procedures are "robust" to minor violations to these assumptions. But how minor are they really? The Bayesian approach should help me to address these two issues.
My approach so far, as suggested by our department statistician, is to recreate my frequentist analysis using Bayesian methods. This is possible by building all of the frequentist assumptions into the Bayesian model as priors. Seems simple enough, but oh no... New procedures, new tools, tool integration, and the same old issue - I have to stop thinking about statistics in the same way... It's hard to break a mental model I have lived with for more than 25 years! Yesterday, I was finally successful. I have now recreated my frequentist analysis using Bayesian methods which builds confidence in the tools and the approach.
The next step in the process is to start modifying the assumptions. My response variable isn't normal it's actually a beta distribution. My prey abundance values aren't normal, but instead are gamma distributions. Can I use a single gamma distribution as the "prior", or are they different for each territory (requiring a heirarchical model). I believe I will end up with the latter. We will see where this continued journey takes me!
Oh yeah, I am also taking and teaching classes. My favorite class of my encore educational career so far has been Behavioral Ecology. The whole class has been fascinating, but my class project involved further depth in sex-ratio manipulation and sex-biased parental investment among various species. Last night I presented a paper on sex-biased filial infanticide (female Eclectus parrots killing their second-born male offspring when nesting is poor quality nest hollows). Fascinating stuff!
Moving forward, I am starting to get excited about year two of my study. I received word last week that it will be funded for another year! Many of my procedures will be the same as last year, but I will need to redesign a few of them. My rock-star field assistant is interested in another year as well. I can hardly wait!

Raptor Research Foundation - Duluth, MN

2011-10-09T18:52:00.001-06:00

I just returned from a fabulous three days in Duluth Minnesota attending the Raptor Research Foundation annual conference. About 200 attendees from all around the world were there presenting their research and hearing about the work of others. I presented the preliminary results of my first field season in the form of a poster.

2011 RRF Poster (click to enlarge).

The poster session featured 24 posters, five of which were presented by Boise State Raptor Biology students! The session was well attended! I had a steady stream of visitors reviewing my poster and asking questions. Discussing my work with the top raptor researchers in the world was fantastic. I was discussing my findings with the people who know the Northern Goshawk as well as anyone. I discussed goshawk diet with falconers, statistics with statisticians, predator-prey relations with prey experts, owls with owl experts (regarding my recent video of a goshawk eating an owl), compared goshawk diets to Cooper's Hawk diets, the challenges of video recording systems, etc. I received strong confirmation of my work, but also great suggestions on how to make it better. It was definitely well worth the investment!

During the presentation sessions, I learned about the current state of pesticides and raptors (not pretty), the state of persecution against raptors (even uglier), the effect of wind farms on raptors (not as bad, but still a significant issue), new statistical approaches (cool, but maybe ugly for some...), and new monitoring techniques (unmanned vehicles!). As I have commented about other conferences, this whirlwind of information was cut down into 20 minute segments. My brain struggled to keep up and change from topic to topic. I have pages of notes to follow up on and have generated over 30 suggestions to integrate into my year one report and my plan for year two. Hopefully I will be able to attend again next year in Vancouver.

Special thanks to the Raptor Research Center at Boise State for partially funding my trip!

Hard-wired!

2011-10-01T14:42:00.001-06:00

One thing you quickly notice when working with predators is that many of them seem hard-wired to attack prey when the opportunity presents itself. This is especially prevalent in predators that do not have a regular feeding schedule. If you may not get another chance to eat in the next week, and there is easy prey in front of you, take it. Even if you have just consumed another meal and could not possibly eat more. This may seem nonsensical to some, but this "attack without thinking" approach is probably what has made many raptors so successful from an evolutionary perspective.
When trapping and handling the various raptor species we come to better understand the different temperaments of the species. While each individual exhibits its own personality, the personalities within a given species are highly similar. My primary study species, the Northern Goshawk, is in a genus known as Accipiter. The three North American species within this genus are reasonably high strung and reasonably hard-wired attack predators. As a result when we are trapping them, we often find that their crop, a storage place in their throat for food, is already full, yet they were trying to attack our lure.
This last Wednesday, while another raptor biology student (Neil) and I were trapping raptors at the Idaho Bird Observatory, Neil captured a hatch year (juvenile) Cooper's Hawk. The crop on the Cooper's Hawk was so full that it even had food in its mouth. Yet this bird was diving to attack a dove! Did it possibly think it could eat more. No, probably not, but it was hard-wired to take prey when it presents itself. Fascinating.

Cooper's Hawk with bulging crop (whole neck area) and a full mouth!

Falco columbarius

2011-09-26T15:58:00.001-06:00

In my not so free time, I have been spending a couple days a week up at one of the two Idaho Bird Observatory raptor trapping stations. On one of the days it is quite crowded as I am participating as part of the "Applied Raptor Biology" course which is required for all Boise State University Raptor Biology students. The other day is my trapping day and if I have been assigned to the Boise Peak trapping station, then I will likely be there all day by myself. I really like Boise Peak and the solitude, but Lucky Peak tends to get more birds.

Last week while at Boise Peak by myself, I trapped my first Merlin (Falco columbarius). I had been working to trap an Adult Red-tailed Hawk which had taken an interest in my lures. He/she had been by twice, but just wouldn't commit. He/she finally landed in a tree in front of the blind and just watched as I tried everything I could to lure him/her in. Nothing worked. Then I noticed a small raptor was mobbing the Red-tailed Hawk. If the Red-tail wouldn't commit, then maybe this bird would. One quick pull on the sparrow lure and I would have my answer. In a flash the raptor turned and like a bullet hit my net. I ran out to retrieve what I must embarrassingly admit I thought was a female Sharp-shinned Hawk. No, it was none other than a Merlin! My first!

Hatch year Merlin, Taiga subspecies (Falco columbarius columbarius)

The trappers all like to catch Merlins as they are fairly rare. They do not breed in our area, but do arrive during the fall migration and stay through the winter. We may catch a dozen or so during a season between our two trapping stations. In this areas we have the opportunity to see all three sub-species, although the Taiga sub-species is the most abundant.

Hatch year Merlin, Taiga subspecies (Falco columbarius columbarius)

Do you know how hard it is to take raptor photos by yourself?

Just two days later I was at Lucky Peak with our raptor class. Neil was trapping, but I was assisting with the sparrow. We saw a bird in the distance and Neil lured him in closer with our larger lures. As he entered the "station" (trapping area) I noticed it was a smaller raptor and pulled the sparrow. Same as before, it turned on the sparrow and hit the net at full speed. Merlin #2! Neil with the assist! I immediately noticed that this bird was considerably darker than the first. Could it be the dark Merlin sub-species (Falco columbarius suckleyi)?

Dark Merlin??

Upon closer inspection and consultation with the IBO Research Director Jay, we determined it was still a likely Taiga subspecies, but could be a hybrid between the Taiga and Dark sub-species. The face looks dark enough, but a true Dark Merlin would not have visible stripes on its tail.

Merlin, Taiga subspecies (Falco columbarius columbarius),
possible hybrid with dark Merlin (F. c. suckleyi)

I have no complaints. While they are the same sub-species, I trapped two Merlins in three days. Not bad. There is still five weeks of trapping to go. Maybe another Merlin sub-species or higher on my wish list, a large falcon (Peregrine or Prairie). I'll keep you posted...

Celebrating Vultures Through Art

2011-09-05T08:31:00.000-06:00

Karyn and I had the honor of volunteering at the Peregrine Fund's World Center for Birds of Prey on International Vulture Awareness Day. Karyn was contacted for her artistic skills and abilities, I was merely there for additional support. We were asked to lead a children's activity of a group painting of a vulture (each child paints a bit of the painting). For those of you who know the two of us personally, working with a large group of children was a terrifying prospect.

It all began a few months ago when our friend from Nairobi Kenya, Dr. Munir Virani, contacted us asking if we would participate (check out his amazing photography at his link). He would be in Boise for the event to talk about the huge decline in African and Indian vulture populations. He was interested in modeling a children's art project after a very successful program that was implemented in Kenya. We happily agreed, and then wondered what we got ourselves into!

Karyn performed all of the prep work in acquiring all of the supplies, sketching out some initial designs, and putting together a plan of how it would all work! The sketches were based on initial photographs provided by the Peregrine Fund. Neither of us knew what to expect and what the finished product might look like. We also didn't know how many paintings might be needed. Karyn decided to produce three sketches, we started with a California Condor in flight.

Initial sketches.

California Condor. The first strokes by a 2 year old.

Karyn with our first artist!

One of the challenges was to assign painting tasks to the various abilities within the groups of kids. The younger ones focused on the broad painting tasks like the sky, while the older ones filled in the detail.

Karyn had the original reference photo available and also a small rendition that she painted to help guide the progress, but all of the paint on the canvas was put there by the kids themselves.

Progress.

Another activity for the kids was to create vulture masks. Here we have a vulture painting a vulture!

Vulture painting a vulture!

More progress.

Starting to come together!

Progress.

It was very manageable when only one or two kids were working at a time. Then a rush of 6 to 8 at a time! Trying to make sure they had mixed paint available, didn't destroy the painting etc. was a challenge. Many were painting over other's work. In most cases it improved the overall presentation!

Five brushes at a time!

Amazing progress!

Finishing Touches.

The completed work! AMAZING!

The artists and their ages.

Near the end of the day we started the second painting. This one would not be finished, but it was great to have another one to work on.

Painting #2.

It was a hectic and stressful day. Both Karyn and I were exhausted at the end of the day. Of course, I was only the assistant. This was mainly Karyn's show as the photos illustrate. By all accounts it was a tremendously successful event. I believe everyone had a great time and learned a lot about vultures in the process.

Other events during the day included presentations by Chris Parish on the California Condor program, Dr. Virani on the African Vulture program, and flight displays of many live raptors including a Harpy Eagle, Peregrine Falcon, Gyrfalcon and Aplomado Falcon. The Peregrine Fund put on a great educational event, which I hope will further the cause to help protect these fabulous creates. I am glad that we were able to contribute to the cause. You can too by educating yourself on the plight of vultures around the world and consider donating to The Peregrine Fund. They have a proven track record in achieving results on the ground (or I should say in "in the air")! I thank them and all of the families that participated!

Luigi - The Harpy Eagle with trainer.

Juvenile Aplomado Falcon in flight.

The Great Escape

2011-08-29T20:26:00.000-06:00

This video captures a mistake by an adult goshawk. The female goshawk delivers a Belding's Ground Squirrel to the nest. Upon arrival she sees an uneaten bird waiting. She feeds the bird to the nestlings, then flies off leaving the dead Belding's Ground Squirrel behind. One problem - it isn't dead. (video plays in double time. female leaves at minute 2:30)

False Negatives

2011-08-22T09:23:00.001-06:00

I continue to analyze the data gathered in my first field season studying Northern Goshawks in the Sawtooth National Forest as a part of my Masters program in Raptor Biology. This is a continuation of my first post on the analysis process. I actually received requests from MULTIPLE people asking me to continue blogging on the analysis phase of my project. So, hold on tight and stick with me, I will try to make this as painless as possible!

First nest discovered with nestlings!

In the first post, I illustrated using straight-forward confidence intervals that avian abundance was a significant predictor for goshawk nest occupancy and success. Here I will highlight another more sophisticated approach to arrive at a very similar answer. Then I will discuss the problem with these two approaches and why these are no longer valid for this particular case and l talk a little bit about where I will be taking it from here.

In the previous post I introduced the concept of AIC based model selection. I mentioned that in ecological studies it is now a foundational expectation for data analysis. Here I will illustrate analyzing nest occupancy and success using AIC model selection.

The first step is to hypothesize which variables should be predictors for nest occupancy and success. An important constraint is that you need to limit the number of possible explanatory variables, based on the sample size. There are different rules of thumb, but one is that you must have 10 samples for each variable, some say five. I am going to stretch this a bit and try three variables for 24 samples. I predict that Avian prey abundance and Mammalian prey abundance, are significant predictors. I also want to include the percent of the territory in sagebrush habitat (versus forested habitat) as I believe that has affected my abundance measurements. The first step is to ensure that none of the predictor variables are overly correlated. For this I will set a threshold for the correlation coefficient greater than 0.70.

Graph of relationships with correlation coefficients.

The graph indicates a low amount of correlation between the predictor variables (0.24, -0.29, 0.34). This was a surprise as I expected the mammalian abundance to be highly correlated to the amount of sagebrush habitat (seemed that we saw more mammals in open habitat). But, low correlation coefficients are good. I have then calculated the AIC values (actually AICc values which are AIC values adjusted for small sample size) for each of the eight combinations of these three variables as predictors for nest success, including the null model (no predictor). There are ranked based on the lowest AICc values. This analysis indicates that the model using mammalian abundance and avian abundance best explains the data, although the model using only avian abundance is very close (within 2 AICc can be assumed roughly equivalent). There are various approaches to moving forward from here: 1. Use the top model; 2. "Model Average" those within 2 AICc; 3. "Model Average" those within 4 AICc; 4. "Model Average" all eight models. Some have even recommended model averaging within 10 AICc. Here I will simply take the top model, create coefficient estimates, and 95% confidence intervals for the coefficients. If the confidence intervals do not include 0, then we can assume that predictor to have a significant influence.

From Drop Box

From this we can take away that a model of both Mammalian prey abundance and Avian prey abundance best predicts nest occupancy and success, and that the influence of Avian prey abundance is significant (confidence interval does not overlap with zero). Hmm, that was the same answer as the previous analysis!

The Problem

But, there is a problem with both of these analyses. They both have an issue of "False Negatives". In these analyses, I had 8 successful nests and 16 failed or unoccupied nests. The issue is that I don't know for sure that there was not a successful nest in one of the 16 territories that we failed to discover. The "No Nest Detected" territories could have one of three values: 1. There was no occupied nest there; 2. There was a nest there but it failed before we detected it; 3. There was a nest there and it was successful, but we failed to detect it. Of course, this last category is very troublesome. For large conspicuous creatures, you might assume this probability is very, very low. For goshawks it is not low. We have walked right under nests without seeing them. We know this as we discovered it later.

Rosenstock et al. (2002) analyzed 224 papers published in nine different journals between 1989 and 1998 and found that only 13% of these studies acknowledged and addressed the case of false negative detections. The bar for publication is clearly higher today.

The Solution

The solution to this issue is to include the detection probability into the analysis. Essentially, instead of saying a territory is "not occupied", we say the territory has a X% probability of being occupied and successful. The whole statistical approach changes. The challenge is determining whether the detection probability is constant, what it is, and what it depends upon. There are a number of ways to generate this, which I am still investigating. At a minimum I will use the values provided by Woodbridge and Hargis (2006), who have analyzed the discovery method I utilized in the field and determined it has a 90% detection rate. I should say that having used the methodology in the field, I believe that they are being quite optimistic!

That's it for now. Thanks for sticking with me. More to come. I welcome your feedback.

The Hunt for Wolverines in Glacier National Park

2011-08-19T13:38:00.001-06:00

This last year, Karyn and I read a book titled, "The Wolverine Way".

This amazing book provides some great insight into the behavior of this very elusive creature that most of us will never see in the wild. It also highlights some of the conditions which the researchers must face to study an animal which spends its life in the very high rugged terrain which is not very hospitable to humans. Any time I am having a bad day in the field, I think of what these guys had to face on a daily basis and that helps to reset my expectations. I highly recommend this book for research, wildlife lovers, or anyone who just appreciates a good story.

Anyway, reading this book inspired us to return to Glacier National Park, even though we might have just as good of an opportunity to see a Wolverine in Idaho. We have visited Glacier on a few occasions in the past. First as a bike tour we traveled from Missoula, up and over Logan Pass and into Waterton Canada and back. Later we returned for a hiking trip. This years trip would be focused solely on hiking with an emphasis on trails will the highest chance of seeing a Wolverine. We wouldn't find any wolverines, but the trip was spectacular. (click on any photos to enlarge)

Sunrise on the East side of Glacier National Park.

View over Redrock Lake toward Swiftcurrent Pass

The Hikes

The Highline trail is one of the most popular trails in the park for serious hikers and those. The trails is relatively easy if taken from Logan Pass to the Loop, where you can catch a park shuttle back to the top. This path is 11.5 miles, only gains 800 feet, but drops close to 3000 feet. However, the 0.75 mile side trip up to the Grinnell Glacier Overlook is strenuous, but HIGHLY recommended. With the side trip it finishes at about 13 miles. The trip is spectacular with amazing vistas and great wildlife - goats, sheep, eagles, marmots, etc. It is clearly my favorite trail in the park.

Early in Highline Trail Hike. Going-to-the-sun road is visible below.

Beargrass looking back toward start of Highline Trail.

Karyn at Grinnell Glacier Overlook.

Grinnell Glacier from Overlook.

Many of the trails were closed due to bear activity. On our hike into Trout Lake we were turned around after meeting a couple that had just had a very close aggressive encounter with a Grizzly Bear with a cub. They were actually charged by the female. Ptarmigan Tunnel, Iceberg Lake and Grinnell Glacier trails were also closed. From Many Glacier only two of the longer day hikes was available - Cracker Lake and Swiftcurrent Pass. We chose the pass.

Swiftcurrent Pass trail heads up from Many Glacier, past a number of lakes and crosses over Swiftcurrent Pass just above the Granite Chalet (on the Highline Trail). Thus, we would end up less than a mile from where we had been a few days before. The trail was once again filled with wildlife including our own bear encounter, although this one was a black bear at about 100 yards. We easily slipped by and continued on our way. The trail passes a few lakes before hitting the head of the canyon and turning into switchbacks. Each switchback provided a new more amazing view until we made it to the summit at 6.8 miles. This trail was an out and back so we were able to enjoy the views again on the way back down along with answering everyone's questions about how much further it was to the top. Quite a few people were headed up behind us as this was one of the few trails still open.

Head of Swiftcurrent Canyon. Where is that wolverine???

View from where we came (started the day 5 lakes down valley).

Virginia Falls, short hike.

On the final day in the park we enjoyed the short trail from the top of Logan Pass, opposite the Highline Trail, which heads into Hidden Lake. The early morning lighting provided fantastic scenery and up-close encounters with wildlife.

Clements Mountain from Hidden Lake Trail

Hidden Lake from Hidden Lake Overlook.

Beargrass.

The Wildlife

While the wolverine remained elusive, we did see lots of other wildlife. Here is a sampling from the week. A Golden Eagle amazed us on the Highline Trail as it pursued Ground Squirrels and Hoary Marmots. As multiple species alarm calls echoed across this landscape this guy flew in and dove toward the prey, but came up with empty talons. It isn't often you get to watch raptors from above!

Golden Eagle approaching prey on Highline trail.

Golden Eagle coming around for a second chance (Highline Trail).

Golden Eagle, Highline Trail.

It's fun to watch people in the parking lots look through binoculars at mountain goats a mile away. Just a short distance down a trail and you sometimes have to leave the trail to get around them. On the highline Trail we came face to face with a mountain goat. It was clear he had no intention of leaving the trail. We stepped to the outside, but he would not pass. I realized this would box him in. We stepped to the inside and he marched right on by, almost brushing up against us.

Mountain Goat demanding the trail (Highline Trail).

Mountain Goat (Highline Trail).

Mountain Goat sleeping ON Hidden Lake Overlook platform.

Bighorn Sheep aren't quite as conspicuous, but we still saw them on many occasions.

Bighorn Sheep (Hidden Lake Trail).

Bighorn Sheep (Going-to-the-Sun Road)

One of my favorite animals, is the Hoary Marmot. These large rodents really show their personality when you watch them. They are also an important prey species for the Wolverine! We found them at the higher elevations on most of the trails we hiked. A number of juveniles were out and about as well.

Hoary Marmot (Highline Trail).

Juvenile Hoary Marmot (Hidden Lake Trail).

I was hoping to see White-tailed Ptarmigans, but they too remained elusive. Of course, we weren't allowed to hike the Ptarmigan Tunnel trail, I am sure we would have found them there! On the Swiftcurrent Pass hike we did find three families of Dusky Grouse (right near the bear).

Dusky Grouse.

It was an amazing trip with the Highline Trail hike being the favorite. I highly recommend it and can't wait to go back to this amazing place.

Maybe a white-faced meadowhawk? Dragonflies are not my thing...

Time off - time to head back into the woods!

2011-08-06T12:31:00.001-06:00

After a big field season studying Northern Goshawks in the woods, it was time for a little down time - in the woods! Karyn and I traveled to central Idaho to celebrate our anniversary. Seventeen years ago we were married on a mountain bike trail near Stanley, Idaho. Each year we spend a week in the area relaxing, playing and celebrating the festive event. This year we once again had a great time. Here is a photo tour of some of what we saw. As you can derive, we had gorgeous weather! (click any photo to enlarge)

Mount McGown on northern tip of Sawtooth Mountains.

One of many elk herds we saw - most with healthy calves.

The Stanley area is a great area for nesting Sandhill Cranes. We would see approximately 20 pairs, many with colts, some with two.

Sandhill Cranes.

Sandhill Cranes, Elk, Canada Geese.

Osprey launching an attack.

One day we took the boat across Redfish Lake to hike into the central Sawtooths. We had hoped to go to Saddleback Lakes, but the water was very high and we could not find a safe crossing. We headed to Alpine Lake instead (in Redfish drainage, there are two other Alpine Lakes in the Sawtooths!). While there I noticed tracks heading straight up the snow field behind the lake. Could they be wolverine tracks?

Alpine Lake, Redfish drainage, Sawtooth Mountains

Path of potential wolverine tracks outlined in red.

The pronghorn are doing well. More than half of the herd are calves. There must have been a lot of twins in this group this year.

Pronghorn on Decker Flat.

Stanley has quite a few beaver colonies. We like to explore these for birds and other wildlife. The dam has been destroyed in our favorite area and hasn't been repaired for two years. The beavers must be gone. The result is that the bird numbers are also down in that area. This year we found a few new areas to explore.

Western Wood-Pewee.

Common Merganser Juveniles.

Juvenile Bald Eagles.

Northern Goshawk food! - Red Tree Squirrel.

Baby Killdeer.

On the final day of our trip we moved our campsite out to Bear Valley to look for wolves and to float Bear Valley Creek in the morning. We were surrounded by elk all night, but did not hear a single howl. It's a crime against wildlife that we have removed this predator from this fabulous ecosystem. From our van we could see a dozen Sandhill cranes, three elk herds, deer, a family of Northern Harriers, Osprey, etc. It's a beautiful location. In the morning we launched our inflatable kayak for the journey down the river. It takes about two hours and is spectacular.

Cliff Swallows!

Bear Valley Creek.

Self anniversary portrait!

Research Publication

2011-08-05T06:21:00.001-06:00

In May, the journal of the Coopers' Ornithological Society - The Condor, published my research on avian migration. I have the full pdf of the article which I am able to distribute upon request. If you are interested in reading it, send me a message or comment on this post. It is also available via jstor if you have institutional access or are a Coopers member. It should also be on the Idaho Bird Observatory site sometime soon.

Miller, R. A., J. D. Carlisle, and G. S. Kaltenecker. 2011. “Effects of regional cold fronts and localized weather phenomena on autumn migration of raptors and landbirds in southwest Idaho.” Condor 113 (2): 274-283.

Male Northern Goshawk Brings Dinner Then Takes It Away

2011-08-03T16:36:00.001-06:00

Male goshawk delivers a baby bird to his nestling. With the female absent he appears not to know how to feed the nestling. The nestling tries to eat, then the male takes the food away. Note: the female usually feeds the nestling and it is common to take uneaten food out of the nest. The food is usually cached nearby.

Plucking the data for the verdict

2011-07-31T18:27:00.001-06:00

The data analysis has begun! Now that my first field season of studying Northern Goshawks in the Sawtooth National Forest is complete, I have started to analyze the data. This will involve watching 3 months worth of video and performing many elaborate statistical procedures. The first analysis I have chosen to focus on is determining the prey abundance in each of the Northern Goshawk territories. These values will be used in further calculations in future steps of my analysis. Here I present what I hope is a simplified description of the process. Don't be frightened, I will try to make it as straight forward as possible.

For background on this project, these links to previous posts might be useful:

Introduction: The Study Begins
Summary of field work: Mission Accomplished
Project support: It takes a village...
Early view of data: Trends in the data...
A retrospective: Blinded by Science

One of my key thesis questions is whether or not prey abundance influences Northern Goshawk nest occupancy and success. Further, which prey items have the greatest influence. The first step, and the step summarized here, is focused on prey abundance. This data was gathered by performing linear transect surveys within each historic Northern Goshawk territory. As each survey is performed, we logged the perpendicular distance of the prey item from the transect "line" by measuring it with a rangefinder. Prey could be detected by sight or sound. My field partner Lauren and I walked 96 transects, each 750 meters long, noting each prey item we detected and its distance from the line. Each goshawk territory had four of these transects randomly placed within its bounds. We tried our best to spread the surveys out over the nine weeks of the project, but late access to a number of territories prevented this. We also attempted to ensure that each of us performed two surveys in each territory. Scheduling also prevented this, but we were able to ensure that we each of us covered at least one of the surveys in each territory. This procedure resulted in 507 observations of prey items along with a number of non-prey items - coyotes, deer, elk, moose, cows, Red-tailed Hawks, Common Ravens, etc.

The theory behind this process assumes that it is easy to detect prey items on the line, but "detection rate" decreases with distance from the line. 0 meters is easier than 20 meters, which is easier than 40m, etc. Once a full set of data is collected, you would expect more detections near the line, dropping off with distance from the line. In fact the method assumes that the detection rate is 100% on the line and drops off from there. 100% detection on the line is rarely possible, but the procedures are fairly robust against some violation of this assumption. Mathematically a function can be applied to the data which models the observations recorded and this can be used to estimate abundance within a given area. Don't worry if you are a little lost. It's complicated, but should be more clear as I present the results below.

I am using a more sophisticated approach within the process which allows for the inclusion of covariates. Covariates consist of any conditions which might change the detection of the animals. The method I used allows for covariates to influence the scope of the detection function, but not the shape. In my case, this assumption is valid. An example of a covariate is the day of the year. We would expect some prey to be more or less abundant or more or less easily detected as the season progresses. Thus, the day of the year the individual survey was performed is probably the most common covariate used in this type of study. Time of day is a second covariate I am evaluating. It seemed like some prey was more easily detected later in the day. Who performed the survey is an important factor. Lauren and I have different experiences, knowledge, and recognition of prey species. Thus, the method allows for adjustments to be made based on who performed which survey. For example, I emphasized strongly to Lauren to "mind the line". In other words, she should devote a large amount of focus on detecting all animals on the line and less away from the line. It is clear from the data that she did this. I, however, have lower detection rate on the line than 10-20 meters away. Ooops. The great news is that our two surveys combined together look great! There are other biases influenced by who performed the survey. For example, I detected Green-tailed Towhees by sight and by call, but not by song. Lauren detected by sight only. The procedures are robust in handling these differences as long as who performed the survey is considered as a covariate. The 4th covariate I am evaluating was recorded on each observation as to whether the animal was seen or heard. The data show what you might expect that observing animals by sight is limited to those closer to the line, where observing by sound extends out much more evenly to about 50 meters. The last covariate deals with the distance of the survey that was performed in open sage/grass versus in forested habitat. Remember the surveys were laid out randomly across the landscape. This one is tricky as we were often walking in sage by a forest stand where the bird was observed. We did not record the habitat of each observation, only the structure of the transect. Next year I may collect more detailed habitat information.

After entering all of the data, the first step in the process is referred to as exploratory data analysis (Thomas et al. 2010). In this process, the data is checked against the assumptions and the covariates are evaluated for importance. This used a fairly complicated model selection procedure called Akaike Information Criterion (AIC). This method has become the standard in ecological research and is one I used in my undergraduate research (Miller et al. 2011). The good news is that unless performing the research you don't have to understand the method, only how to interpret the results. The process is to calculate an AIC value for each combination (or only the relevant combinations) of covariates. In our case, all of the covariates appeared to be relevant. Five covariates produced 32 combinations including the model with no covariates. The AIC score represent how well that model or combination of covariates fit the data that was recorded. Essentially choose the model with the lowest AIC value. Sometimes you could choose a model with an AIC within 2 points which includes fewer covariates (within 2 points is considered roughly equivalent. Generally fewer covariates are better, but AIC does penalize the use of too many, so most people just choose the lowest AIC. I should note the AIC value is meaningless except for comparison between models using the EXACT SAME data. Blah, blah, blah, I hope that wasn't too much theory...

So after entering all of the data, I started the model selection for the covariates. I have chosen to process birds and mammals separately as they are generally detected in different ways, are detected at different distances, and are of different size and thus could have different impact on the diet of goshawks. Also note that we are only including prey items for goshawks. We did not count small warblers of which a nestling goshawk would have to eat 40-50 a day. While goshawks may occasionally eat small prey, that prey is not likely to have an important impact on nest success. For birds we included robins, woodpeckers, doves, tanagers, towhees, bluebirds, blackbirds, and grouse. Mammals included ground squirrels and chipmunks. The following table shows the mammal output for the top models. Note the smallest AIC is at the top. Most AIC tables, like this one, include a delta AIC which performs the math for you. The top model is 0 and the delta AIC indicates the AIC difference from the top model.

Name	# params	Delta AIC	AIC
Mammal Time Who	3	0.00	393.12
Mammal Julian Time Who	4	0.93	394.05
Mammal Time Who Seen	4	1.25	394.37
Mammal Time Who Sage	4	1.83	394.95
Mammal Who	2	1.90	395.02
Mammal Julian Time Who Seen	5	2.05	395.17
Mammal Julian Time Who Sage	5	2.80	395.92
Mammal Who Sage	3	3.22	396.34
Mammal Time Who Seen Sage	5	3.24	396.35
Mammal Who Seen	3	3.50	396.61
Mammal Julian Who	3	3.70	396.82
Mammal Julian Time Who Seen Sage	6	4.05	397.17

Here we can see the top model for Mammals only uses the time of day of the survey and who performed the survey, dropping the other potential covariates and simplifying the model. The bottom line is that ground squirrels were more easily detected later in the day and Lauren and I detected them differently. The analysis of bird detections chose a model using the day of year, who performed the survey, whether they were seen or heard the bird, and the amount of survey performed in open sage/grass versus forest. Excellent.

Now lets see how the data look once they are adjusted by these covariates, extreme values are truncated, and data is grouped into 10 meter buckets to smooth the curve. Mammals came out looking exactly like it should, as illustrated in the graph below! The sampled data is in blue and the "fitted curve" is in red. The fitted curve will be used to estimate abundance in each territory.

Sampled mammal data (blue) and fitted curve (red).

This may not look exciting, but it is absolutely awesome! This illustrates that my survey method worked. Not only did it work, it worked great! I was ecstatic when I first saw this. As scientists we like to find significant results, but we like even more to implement methods that when executed produce valid results. This did just that!

The avian results, as illustrated below, are not quite as clean due to a "training and assumption" issue in our field methods. The only issue is the increased detection probability near 50m. As you can see from the curve below, it had little influence on the fitted model and falls well within the bounds of the methodology. The end effect is potentially a slight under estimate of abundance within each territory, applied consistently across all of my territories. Since I am using abundance as a relative measure, the end effect is irrelevant.

Sampled bird data (blue) and fitted curve (red).

Thanks for sticking with me. All of this work simply leads us to the conclusion that the method works, the data is valid, and abundance estimates produced can be used in the next steps of my analysis. It is often the case that more work is required to prove the method than to interpret the results.

Now, on to the real results. I categorized each of the goshawk nesting territories as either "no occupied nest detected", "occupied nest that failed", or "occupied nest that successfully fledged young". Calculating mammal and avian prey abundance in each of these territories, we can compare the results between these categories. Mammalian prey abundance did not have a significant impact on nest occupancy or nest success. This is a bit of a surprise as we know from the not yet quantified camera footage and personal observation, that goshawks in the South Hills do eat a lot of ground squirrels.

Mammalian prey abundance in goshawk territories categorized by success - not significant.

A significant result would occur if the bar height of one bar fell outside of the "whiskers" on another bar. The bar represents the expected value and the whiskers represent the range within the true value should fall with 95% confidence. If a bar were to fall outside the 95% confidence of another category, we could call it significantly different. In this case none of the bars fall outside of the whiskers of any other bar. The whiskers on the "breeding, nest failed" bar are larger since there are only two territories in this category. Fewer samples result in larger uncertainty and a wider range of possible values. But, the avian prey results are significant!!

Avian abundance is a significant predictor of nest success!.

If you think I was excited before, this is outstanding! This illustrates that avian prey abundance in successful and breeding/failed territories are both significantly different than avian prey abundance in territories where no nest was detected. Although, the abundance between successful and failed nests is not significant. This far exceeds my expectations for my first field season! Awesome!

Why might avian prey abundance be significant while mammals are not. I will leave most of this for the discussion section of my research publication, but a likely answer is that nest occupancy is determined by two factors - past breeding success and prey abundance in February/March when the territories are chosen. Ground squirrels are unavailable in Feb/March and thus don't likely influence initial occupancy. Past success is dependent upon many phases including early spring, breeding season, and the post fledging dependency period (time after birds fledge but before they are independent from their parents). During this later period ground squirrels begin to estivate (summer hibernation) and the goshawk diet has to shift back to birds. Thus, birds early and late may possibly be the limiting factor to success. This theory would be consistent with my results. If you made it this far send me an email or post a comment so I know that this write-up was valuable.

I should note these results are still preliminary and I have months worth of further work and analysis to do. I will plan to provide other analysis updates as I make progress. I plan to present these results and the next few analysis steps at the annual Raptor Research Foundation conference in Duluth MN in early October (their logo is even a goshawk!).

Blinded by science

2011-07-28T08:13:00.001-06:00

Actually, the title should read blinded by bad assumptions while in the field performing science! I have previously written of my adventures studying Northern Goshawks in the South Hills of the Sawtooth National Forest of Idaho. In the previous reports I have noted the discovery of a dead male goshawk in one of the nesting territories we were studying. Well, not so fast...

One of the nesting territories of my study remained inaccessible until very late in the season due to snow. Once we did arrive in the territory, I quickly received a response from a adult female goshawk. Her response was consistent with the presence of a nest very close. The presumed nest stand was fairly small, but after numerous searches we failed to find a nest. However, the female goshawk was easy to find in the same stand day after day.

One day Lauren found a pile of feathers about 150m from where we usually found the female. The feathers were definitely raptor feathers and seemed consistent with a goshawk, although we did not have a feather reference with us.

Feathers discovered in the South Hills.

Due to the territory where the feathers were found and the proximity to the female goshawk, we assumed this pile of feathers belonged to the male goshawk of the territory. This one assumption played a critical role in our interpretation of the female goshawk behavior as I will illustrate below. However, upon further inspection...

Returning home after the season, I accessed the online feather atlas to confirm the identity of the feather owner. They unfortunately do not have male goshawk feathers available, but do have adult female feathers.

Hmm. We have a problem here. The colors don't match, but goshawk colors vary significantly. The shape seems a bit off as well. But the size is the real issue. Our collected feathers are longer than these female goshawk feathers. In most raptors, including goshawks, the female is larger than the male. In goshawks the female can be 15% larger. I would expect male goshawk feathers to be shorter... Well, there is only one other gray raptor in this area. The male Northern Harrier.

Well, that is better, but what about those assumptions...

We observed the female goshawk in the stand on six different days. On each occasion we were there for at least an hour searching and watching her behavior. This behavior was interpreted through our assumption of the male being dead. For example, if the male was dead and the female had a nest with live nestlings she should be hunting most of the time. In our case, she was perched in the stand on every occasion of our visit. This was inconsistent with a nest full of hungry nestlings. On the other hand, if the male was out hunting all of the time then the female could remain back to guard the nest stand. This could be consistent with a nest full of nestlings.

Another challenge in the South Hills is that we would occasionally hear a goshawk call which was unfamiliar. This unique call was omitted from most references regarding goshawk communication. On one occasion the female issued this call and flew like a rocket over my head and to the edge of the stand. With the assumption of the male being dead, I could not explain this behavior. Maybe stand defense? I was confident that her response was not directed at me, but I had previously seen her respond to a Common Raven, but not in this manner. Upon further research I have found one description of a female "dismissal call" which is issued by the female to the male, often as the male delivers food. Could I have witnessed a male prey delivery and not even recognized it? This would be a indication, although not a firm confirmation, of a nest with live nestlings in the area. I have yet to find a recording of the "dismissal call" to confirm this, but we have heard three other females give the same call, on each occasion the male was also present. Once again, the assumption of the male being dead and my lack of experience with the "dismissal call" clouded my interpretation in the field. Yes, experience does matter!

Next week I hope to return to the stand one more time. By this time any nestlings should have fledged, but would still be expected to be in the area. Nestlings are easily identified by their begging calls. Begging calls would allow me to classify the territory are a successful nesting territory even without finding the nest. Otherwise, it will remain as "occupied".

Next year I will definitely have more resources in the field including a printed feather atlas!

Trends in the data...

2011-07-18T16:22:00.000-06:00

As a research biologist I am always looking for patterns in the environment or in the data that I collect that could lead to new conclusions and knowledge about the species we study. Usually these patterns are mostly hidden from view and we rely on statistics to tease them out. During my recent field season I noticed a very strong trend regarding the six non-failed goshawk nests were were monitoring at the end of my seventh week in the field. It appeared that the late spring weather might have had an impact on the number of nestlings. The earliest hatching nest (as determined by the age of the nestling) only had a single nestling, where the two latest hatching nests each had three!. A plot of the six nests looks like this...

Northern Goshawk nestling counts by hatching date for first six nests discovered.

Look at that amazing trend line. Not surprisingly with a pattern like that the trend is very significant. A simple regression has a p value less the 0.001 and an r-square of 0.95. This is unheard of in ecological research. To have such a strong p-value and r-square value with only six points is amazing. This was definitely looking like a strong conclusion. I looked through my research summaries (Book: The Goshawk by Robert Kenward) for other research with the same conclusion. I didn't find any. While this book is not comprehensive, it is nearly so. I became more optimistic that we might be on to something.

During week eight, we performed our job too well. We discovered two more occupied nests and these two did not fit the mold. Adding these two points into the analysis produced a picture that looks like this... (new points in red)

Northern Goshawk nestling counts by hatching date for all eight nests discovered.

The statistical significance goes right out the window... The p-value rises to 0.27 and the R-square drops to 0.06. The only trend remaining in the regression line is almost entirely influenced by the first point.

The lack of significance does not mean that early season nests didn't faced unique challenges affecting brood size, it just means that this study cannot conclude that there is a correlation.

Brood size by hatch date is not part of my thesis, but it might have been nice to have a freebie significant result. Anyway, I would rather have the two new nests for my thesis, which is challenged by sample size, than concluding brood size is related to hatch date.

Mission Accomplished!

2011-07-17T10:27:00.000-06:00

Here's the latest update on the progress I have made during my first field season of my master's thesis project in Raptor Biology studying the Northern Goshawk. This post covers field season weeks 8 & 9. Previous posts in this series:

Introduction: The Study Begins
First week: First week starts with a bang, ends in snowy frustration but renewed optimism
Second week: Two weeks in, three weeks behind...
Third and fourth week: Project is Rolling Now
More on fourth week: The Tale of the Stolen Jacket!
Fifth and sixth week: Black Flies, Bachelors, and Technology Woes
Seventh week: End Game
Project support: It takes a village...

The end of my first field season studying Northern Goshawks has arrived. Well, sort of... I have a one day trip to the area I still need to make. The last trip, not scheduled for a few weeks, will allow me to remove the final nest camera and to perform habitat surveys around the nest trees without disturbing the nestlings/fledglings. I can't believe it is mostly over. I am relieved yet at the same time disappointed. It has been a fantastic experience which I will clearly miss. But, by all measures it was a highly successful season! And for that I am tremendously grateful! It could not have occurred without the support of many.

On my final day in the field, while still amped up on adrenalin from climbing a nest tree, I focused my creativity on poetry. A 40 minute motorcycle ride can do that to a person. Here are my two works of art!

To the South Hills Goshawks I bid you adieu,
I enjoyed our time together probably much more than you,
May the ground squirrels by plenty,
and the Flickers be plump,
I will see you again next May for my thesis year 2!

and

There was a young goshawk affectionately known as Chuck,
when I climbed the nest tree to band her I definitely had to duck,
for the parents were screaming,
and attacking with rage,
but Chuck just stared and said, "Hey, what the ...?"

Yah, yah, yah, I'll stick to field work...

Adult Goshawk.

The season

My early season concern regarding the late spring weather was eventually alleviated. My hope was to discover at least eight occupied goshawk nests. With a couple late discoveries, I ended the season with ten! The early season weather also presented many transportation and access challenges which I have documented in previous posts, but through some long hard days, we managed to get back on track and catch up. We even completed a couple of the stretch goals for the season!

Now comes the long process of analyzing the data. Three months of video footage, data from 100 prey transects, observations from ten goshawk nests, interim reports to write (due in September), final reports to write (due in December), posters to create for presentation to the Raptor Research Foundation annual conference (October), applying for additional funding through grants, and then revising plans for next year. Wow, somehow I feel the work has just begun!

Three nestlings approximately 25 days old.

Goshawks everywhere

One of the new developments during this final field session was a significant increase in the number of sightings of goshawks. As the nestlings age the adult female goshawks are free to spend more time out hunting. This essentially doubles the number of birds visible. This is great, but it can also be frustrating. Visiting a territory a half a dozen times, finding an empty nest, performing multiple prey surveys, systematically searching for nests, performing call broadcasts covering a 577 hectare plot, all with no detections. Then, on the final visit to the territory while riding out on the motorcycle, I watch an adult goshawk fly into the nest stand. Unbelievable! Could I have missed a nest? Could this territory really be occupied? Should I go back and search some more? Probably just a roving adult out on a hunt far from their territory. If this was one isolated incident, maybe it wouldn't be so bad. When it happened again in another territory and then again in a third... well... Hmm... I guess that is why we have a formal protocol.

The case of the mistaken identity. We came to know a particular female goshawk quite well. In a late territory we finally gained access to we had an adult female response to our call playback. The stand was reasonably small, but we were unable to find a nest. There had to be a nest. We discovered a pile of raptor feathers nearby. With goshawks on the brain, we assumed it to be a the adult male. The female could be a widow. Each day we returned, we were able to easily relocate the female in the stand. But the location of a nest and its status remained a mystery. After spending time in the stand on five different days, we gave up on that territory for this year. I still believe there was a nest, but her actions seemed inconsistent with it still being successful, especially being a lone adult. Upon returning home and having access to resources such as the feather atlas, we discovered the feathers to be a male Northern Harrier and not a goshawk! Ooops! This changes our interpretation of the female's behavior. Possibly there is still a successful nest in the area.

One highlight observation occurred one evening while sitting on the porch of our cabin. An adult goshawk swooped by 20 feet in front of us at eye level and flew off through the trees. How cool is that! We travel all over the forest in search of these birds every day and here it was right in front of us.

37 day old nestlings, 4 days before they fledged.

Research on goshawks has occurred off and on in the South Hills over the past 20 years. Most studies, mine included, have focused on the same historic territories. One of my stretch goals was to discover a new territory. With the late spring weather I had all but given up on this, but our progress in the last few weeks re-opened the door. Through the use of GIS techniques I had mapped out the historic territories and analyzed the attributes of those, focusing more on the most successful nesting areas. I combined this with other literature on goshawk preferences and produced an algorithm for discovering new territories. Applying this algorithm to the entire South Hills I came up with seven potential locations. Last week I finally had an opportunity to visit one of them and boom, within an hour I had a detection. Within two more hours I had found an occupied nest with three nestlings! I also found two alternate nests in the area. My sample size just increased and I delivered a new territory to the forest service for future monitoring. I hadn't been this excited since finding my first nest on the first day. It got even better when Lauren reported a detection in the third new area we explored. Unfortunately we did not find a nest there but will return to check it out next year. The other four potential territories will have to wait for next year.

Adult Goshawk.

Nest stand structure and health

Visiting the various territories you definitely get a strong feel for the preferences of goshawks. A number of studies have shown their preference for a thick canopy cover with a relatively open understory. In fact, ground cover in the form of shrubs has a negative correlation with occupancy. Thus, mature Aspen with few saplings and mature Lodgepole with few saplings and shrubs are the places we most often find nests.

The problem with many of the historic nesting territories is that they are progressing beyond the mature stage and cycling back to a young forest. The older mature trees are dying off and often being replaced by young saplings. The result is that the nest stand may become unattractive to goshawks for another 20-30 years. This can be a natural cycle for Aspen. Bark beetle attacks are also killing off the mature Lodgepole pine, also forcing a reset to the succession and causing the stand to lose attractiveness to goshawks. While the primary focus of my study is on the prey relationships, I am also measuring the nest stand structure and health. It may just be coincidence, but one of the failed nests I was monitoring was once an excellent stand for goshawks, but I would no longer choose it for occupancy. Over 1/3 of the mature Aspens are dead and the stand is almost impenetrable due to Aspen saplings everywhere. A few of the Lodgepole Pine stands have been attacked by bark beetles and may be completely gone within 5-10 years. The forest service has a general plan to actively manage stand succession ensuring adequate availability of each successional stage. I have initiated discussions with them on how to integrate goshawk territories into that planning. This is a very exciting opportunity to have a positive impact on the conservation of this species.

Miscellaneous musings

The story of the watch. One funny thing that happened in the South Hills occurred when I was installing a nest camera in one of the trees. Lauren thought she saw a curved twig fall that I had somehow broken off. Later when back at the truck I stopped to see what time it was. Where was my watch? Apparently during the climb the watch had come off my arm. It would now be stuck in the tree for some time. Every morning at 6:00am the goshawks would be awoken by the alarm on my watch. Talk about investigator disturbance! Three weeks later when I would re-climb the same tree to band the nestlings, there it was half way up, hanging on a branch. I can now say that the watch is back in my possession enabling the goshawks to sleep in for the remainder of their nestling phase.

When climbing the nest tree to band the young, we often find prey remains or in some cases whole prey waiting to be eaten. In the same nest that I lost the watch, I found a dead juvenile American Robin sitting in the nest bowl. As I proceeded to band the young, I was discovered by the adults and they began their barrage of attacks. Nothing serious at this nest, simply protests and fly-bys (versus direct attacks to my head that has occurred in other nests). Anyway, at one point the adult male flys up and lands on the nest rim about 2 feet away. I notice that he is carrying another juvenile American Robin. It is possible that these were taken directly from the nest. It is known that Accipiter hawks, of which the goshawk is one, will return to the same source once they discover the nest of a prey species. In two other nests we found whole Belding's Ground Squirrels. It takes a lot of prey to feed a nestling. In other studies, each nestling consumes about 3/4 of a pound of prey a day.

Conclusion

The project has been a fantastic educational experience and I can't wait to get on to analyzing the data. That will be after a short vacation filled with other outdoor activities. But I will miss the daily routine and the fleeting relationship I have had with the wild goshawks of the South Hills. I am sure it happens to all researchers, but my admiration for the goshawks and the challenges they face has only increased with my time. I cherish every observation, even the three occasions that resulted in blood being spilled (mine of course). Back home I keep thinking of the individual birds. Is "Chuck" still slowly expanding his range from the nest (last observed about 100m from the nest tree)? Does the lone female really have a nest? Will it be successful? Two adult males observed were previously banded. Where did they come from? My research is all about the big picture and the population as a whole, but my interactions were all with individuals and I will remember every one.

Two and a half years ago I left a high paying job to spend time working on this in the outdoors. I can honestly and unequivocally say that it was one of the best decisions of my life. While my field work is done for this year (except for the follow up day), I will be working on other projects this fall, most notably banding migrating raptors at Boise Peak. It's a great project, but it's not like working on my own. That will have to wait until next year when I once again return to the South Hills. In the mean time it is all about analyzing the results.

It takes a village...

2011-07-16T06:51:00.001-06:00

Here's the latest update on the progress I have made during my first field season of my master's thesis project in Raptor Biology studying the Northern Goshawk. Previous posts in this series:

Introduction: The Study Begins
First week: First week starts with a bang, ends in snowy frustration but renewed optimism
Second week: Two weeks in, three weeks behind...
Third and fourth week: Project is Rolling Now
More on fourth week: The Tale of the Stolen Jacket!
Fifth and sixth week: Black Flies, Bachelors, and Technology Woes
Seventh week: End Game

Northern Goshawk Adult. South Hills, Idaho.

No, I am not raising a child (reference to African proverb), but a thesis project is a large and challenging undertaking. My specific research has been supported in many ways by many individuals and organizations. I hesitate to list individually, as I am likely to omit an important contributor or two. I apologize in advance if I do. However, here are some of the contributors which helped make my first field season a success.

Financial Support

The Minidoka Ranger District of the Sawtooth National Forest is the primary financial supporter of this research. The Northern Goshawk is a local management indicator species and thus understanding the health of the population and filling in the picture of the goshawk's role in the ecosystem is critically important to them. In addition to the direct financial support, the forest service also provided a cabin within the study area, which was critical especially during the snowy portion of the season and access to important equipment such as an ATV, GPS units, call broadcast units, emergency radios, etc. Support also included GIS data and other coordination activities. This project could definitely not proceed without their support and commitment. Dena, Tom, Jill, Bonnie, Karen, Kirby, Amanda, the trail crew, the fire crew, the recreation crew, ... they all at one point or another crossed our path and helped with something. What a great organization!

Natural Research LTD awarded me the 2011 Mike Madder's Field Research Award! This competitive award provided additional funding which was used to purchase the digital nest cameras which are critical to my core research questions. I thank them for offering this award and their commitment to the advancement of science in Mike Madder's name.

Rob Miller & Karyn deKramer. I would like to be able to say that all project funding came from outside sources. Unfortunately, that is not the case. This project has faced many challenges requiring funds beyond the core budget. Our personal motorcycle also racked up over 1600 miles within the study area. I am grateful that we have been able to cover the required expenses and keep the project on track. I especially thank Karyn for her willingness to share in our support.

Equipment and Support.

This project requires a significant amount of equipment: ATVs, trucks, nest cameras, batteries, GPSs, Rangefinders, climbing gear, etc.

Boise State University's Raptor Research Center provided logistical support, access to a truck and most of the equipment used by the program not provided by the forest service. In many cases they outlay-ed money to repair and replace dated equipment. Dr. Fuller, Kathy and Nikole are a pleasure to work with and have consistently exceeded my expectations in helping me as my project faced challenges.

The Idaho Bird Observatory initiated the discussions which led to this project and provided consultation, contracting, etc. Jay and Greg are a great team to work with and I admire their work to provide opportunities to students such as myself.

Inovus Solar donated a number of rechargable batteries which were used to power the remote nest cameras used in my study. This updated technology increased the feasibility of remote cameras and decreased travel time required in the field to replace them. They worked great!

Greg Kaltenecker not only dedicated his time in the field and the consulting mentioned above, but also contributed gasoline to the cause which helped keep the field crew moving from territory to territory. The study area consist of over 125,000 hectares. From our central location this includes a 20 to 25 mile radius. This is a lot of ground to cover with at least weekly visits to each of the 24 territories.

Volunteers

There were many volunteers through the season. First and foremost, Lauren, who worked long hard days from the beginning through the end. Nine weeks of hiking steep hills, through thick brush and inpenetrable ceanothus, snow, Belding's Ground Squirrel guts, and most importantly, putting up with me! I am forever indebted to her.

Others joined for days up to a week. Some left relieved their time was over, but most left wanting more. Karyn, Jay, Heidi, Dave, Carol, Cathy, Cristen, Uri, Kerry, Nicole, Jeri, Michelle, Dusty, Mike, and Grant, all spent time with Lauren and I in the field. Some provided training, some searched for goshawk nests, some found goshawks nests!, some helped with nest camera installation, etc. Many helped feed the crew as well. Wow, how to thank them all? How did I ever find such great friends?

But it didn't all happen in the field. Advice, perspective, and just listening when I needed to talk. My thesis committee, Jay, Marc, and Jen, all fielded questions via email, text message, and/or phone. I am sure they fear my name appearing on their caller ID! Other goshawk researchers also provided advice via email, some I have never met. Kristin, Susan, and Jack, to name a few, provided insight into how to search for nests, specifics on some of the areas within the South Hills, and in some cases just moral support. It was all appreciated.

I review this list of names and organizations in awe. How did I ever assemble such a team? How will I do it again next year? Some had never heard of a Northern Goshawk before seeing one in the field. They are great people who care deeply about our environment, it's conservation, and what it has to offer. I am honored to call each of them my friend, even the one's I have never met. Thank you!

End Game

2011-07-02T16:15:00.001-06:00

Introduction: The Study Begins
First week: First week starts with a bang, ends in snowy frustration but renewed optimism
Second week: Two weeks in, three weeks behind...
Third and fourth week: Project is Rolling Now
More on fourth week: The Tale of the Stolen Jacket!
Fifth and sixth week: Black Flies, Bachelors, and Technology Woes

Finally we have gained access to all of the historic territories in the South Hills. Not all roads are open due to snow, but we have fairly direct access to most areas with a few minor detours. This next week I expect it all to be available. With the new territory access, we are zeroing in on possibly the ninth occupied nest of the season. In this last territory we received a "vocal female approach" in response to a goshawk call broadcast. That usually means an occupied nest within 200m. The two other times I have witnessed this type of approach, we eventually found the nest. Eight nests is a good sample size, but nine would be better!

We continue to make progress on the prey surveys and completing our search protocol in unfinished areas. Lastly, we have started banding nestlings and continue to maintain the three nest cameras which I have installed.

Nest Cameras

The three nest cameras I have installed (had hoped for five), will be used to quantify the diet of Northern Goshawks within the South Hills. My proposal mentioned that the South Hills lack tree squirrels which have been shown to be the top diet choice of goshawks around the world. Additionally, Lauren will be researching nestling behavior using the same video footage. It is a tremendous resource. While I have not looked through the hours of video, nearly every file I open has some interesting behavioral aspects. I can't wait to discover all of the interesting content included within. Here is a age sequence of the first nestling with a nest camera. This nestling was affectionately named "Chuck". In general we do not name our study individuals, but when I posted my facebook status my fancy Droid phone spell checked the message and changed "Chick" to "Chuck". The name stuck. The short video covers ages of 14 days, 20 days, 28 days, and 35 days old of the same nestling (Chuck).

Prey Surveys

As I have mentioned in previous posts, the primary focus of my thesis is on the predator-prey relationships of Northern Goshawks. To accomplish this we are performing prey surveys in each of the 22 historic territories, independent of whether the territory is occupied or not. The method used is Distance Sampling along line transect. In each territory I have randomly placed four 750m transects. To complete a transect, we walk the 750m and note the perpendicular distance from the line to the prey item. This distance is measured using a laser rangefinder. We count Robins, woodpeckers, ground squirrels, etc. While we occasionally find other prey species such as White-tailed Jackrabbits or Ruffed Grouse, I won't have sufficient sample size to estimate their abundance. The perpendicular distance is entered into a statistical function which uses detection probability to produce an abundance estimate, with confidence intervals, for each territory. This means that you cannot look at the list of prey items seen and estimate abundance. Abundance is a function of both number seen and distance. I remain skeptical but optimistic that I will find a significant result. Some surveys in occupied territories have produced a huge list of prey items, while others have not. Also, all four surveys must be looked at together as the survey routes are placed randomly across different habitat types. To complicate matters I will also include the date, time, and whether the survey was performed by Lauren or myself. These "co-variates" will try to account for the differences in prey presence/detectability through the season, at different times of day, and the fact that Lauren and I will see/detect different species/individuals, etc. The calculations are very complex indeed. It's a good thing that there is a special software program called "DISTANCE" which will do most of the heavy lifting. It will be another couple months before I know for sure what I have got.

Another challenge with the prey surveys is that they are randomly placed across the landscape, not on trails or roads. In fact, they cannot be placed on trails and roads as this would bias the results. The effect is that they sometimes lead over cliffs, head straight up the mountainside, pass straight through impenetrable shrubbery (Ceanothus!) ,are miles from the nearest access point, or a combination of these. This last week while hiking in the deeper canyons in the south, some surveys required hiking to the bottom of the canyon to start, completing the survey by hiking straight up the other side, hiking back across to the vehicle, then moving to the next territory to repeat. It was our toughest week to date.

Regardless, this past week we did get caught up on surveys, completing three in each of the territories. Next week we will complete the remaining.

Nestling Banding

Last week's post included some photos of my first experience banding nestlings in the nest. As you can imagine, the nestling "Chuck" was not pleased with the encounter.

Chuck protesting my arrival.

Here is the video sequence of the banding as captured on the nest camera.

It was quite a challenge hanging in the tree, working on the bird, all while the adult is attacking me. This week, my field partner Lauren climbed and banded her first nestlings.

Starting the climb.

Nestling looking over the rim.

30 foot climb.

Banding two nestlings.

Lauren was a bit luckier than I as the adults did not attack her. In fact both adults were away hunting for the first half of the banding process. One adult returned with some prey, probably the male, called out and then flew off. The female would have likely put up a stronger defense if she was around. Lauren had a small challenge on the descent as her feet had fallen asleep while at the nest. We often rappel out of the nest, but this tree did not have a suitable rappel anchor. Lauren therefore had to downclimb the tree with her feet asleep. I am happy to report that while it wasn't pretty, she made it down safely! Next week we will be climbing two more nests to complete nestling banding. One of the nesting areas has been very heavily defended by both adults (see reference to "scalped" in previous blog post!). The defense is so strong that we have yet to see or count the nestlings. I will definitely be wearing armor for that!

The locals

One of the interesting aspects of field work is interacting with other people in the field. For the first half of the season we rarely saw other people. The South Hills are now crowded with people providing numerous opportunities for interactions, both positive and not so positive.

The first group were three men on a beer break one afternoon. We stopped to say hello. After informing us that anyone from Boise must be lost (Boise State logo on side of our truck), they proceeded to inquire about our work. Raptors? Hawks? "They taste good!" Better than those black ones with the red heads (Turkey Vultures). We enjoyed the laughs. They then invited us to their cabin for a beer drinking contest. My guess is that Lauren, I, and six friends would still lose! Nice guys, they even told us where they keep the beer! As he said: "20 minutes in the spring water and the mountains turn blue!" (reference to Coors Light labels that change color when chilled). We are contemplating paying them a visit next week, although we have no illusions of the beer drinking contest...

The sound of gunfire is not uncommon in the South Hills. It is very unsettling when you know that you are probably the first person the people with guns have seen in hours. They do not expect you to be there. When people are traveling by ATV and shooting high powered rifles out of hunting season, I am not sure what to expect. They clearly were not sighting their rifles or target practicing, unless their targets were moving as there were a series of gunshots, they would move, a series more, etc. Hmmm. On the topic of guns, I found myself one morning on a prey survey walking into an area where kids were shooting pellet guns. Pellet guns don't make much noise, so I as completely surprised. I kindly requested that they pause until I had cleared the area. They looked at me like I was from another planet! But they didn't shoot me so I guess that was good...

Trying to help. Lauren also had an interesting encounter. In the middle of nowhere in the Southern part of the South Hills, she sees a dog. No one to be seen for miles in any direction. She stops the ATV and calls the dog to see if she could help. Suddenly a woman comes over the hill and asks what she was doing messing with her dog. Apparently, the explanation still didn't settle her down.

The bottom line is that there are many great people out there and a few that aren't so great. It is always wise to stay alert.

Almost Done

Next week we head back out for our last ten days in the field. We will be busy and I expect it to fly by. It's hard to imagine that the end is almost here. But our schedule is dictated by the birds and the seasons. Chuck will likely have fledged by the time we return if he hasn't done so already. The other nestlings will not be far behind. The odds are stacked against them all. An estimated 70% will not live until June of next year. 80-90% will not live to see their second birthday when they will first mate. But those that do will be all the stronger for it, as will their offspring. I hope that some of these nestlings will be the ones to make it. The leg bands that we have applied will help to tell their story. Lets hope its a good one.

Of course, the end of the field season only means the start of the analysis. Over the next six months I will be watching video, analyzing data, writing reports, creating posters, and presenting results at conferences. Then begins the work of modifying procedures for my second field season on which it will all start again.

A sea of wildflowers!

It's hard to imagine my days (21 years!) working in the high tech industry. This world is so far from that one. I cherish every day of this new encore career, even the cold, wet, miserable ones and the hot, dry miserable ones! Look for another update in a couple of weeks time.

Black Flies, Bachelors, and Technology Woes

2011-06-23T19:33:00.001-06:00

Here's the latest update on the progress I have made during my first field season of my master's thesis project in Raptor Biology studying the Northern Goshawk. This post covers weeks five and six. Previous posts:

Introduction: The Study Begins
First week: First week starts with a bang, ends in snowy frustration but renewed optimism
Second week: Two weeks in, three weeks behind...
Third and fourth week: Project is Rolling Now
More on fourth week: The Tale of the Stolen Jacket!

The project has been progressing very well. We have accomplished more during the past two weeks than during the first four weeks. The melting snow, day by day makes our jobs easier, but also opens up new territories where work needs to get done. The learning continues to progress at a rapid rate and I am more and more optimistic about the project. Both Lauren and I continue to improve our skills as well. I am more and more comfortable in the tree climbing arena, with four climbs under my belt. On a personal convenience front, we now have water in the cabin! It arrived just in time for the hot sweaty weather. Unfortunately, 1,000 of our friends on ATVs have also arrived, but I guess we can't claim the entire place to ourselves any longer.

Working in the field

One of the most important things I like about field work is being in the field exploring and working to interpret what the surroundings have to say. There are some researchers who can simply take data from field assistants and synthesize it into research manuscripts without ever getting their feet dirty. I am not one of those. I believe the data is critically important, but I often get the interpretation from my experiences and observations which were not designed into the protocol. For my undergraduate research, which has just hit the presses in the Journal the Condor, it was instrumental that I participate in the bird banding and raptor counting to get a sense for what answers I should be looking for in the data. It is when the data agrees and disagrees with personal observations that can drive to the next set of questions.

One of the questions we are looking into in the South Hills is whether this population of Northern Goshawks are doing well. Additionally, I am looking into what influences within the environment, most notably prey availability, may be influencing that success. Whether prey is the primary influence, will have to wait for my thesis, but there are other theories out there. One theory is that this population is not doing well. In a ten year study documented by Kaltenecker et al. 2004, there was no evidence that goshawks raised in the South Hills returned to breed there. General raptor life history would predict that male offspring would return to their natal area to breed. A potential cause of no returning nestlings could be high mortality to a black fly blood parasite which attacks the nestlings and the female while on the nest. I am not studying blood parasites, but I can attest to the black fly as a potential vector. On the third nest I entered, the nestlings were covered in black flies. A few other nests I have observed have had similar issues. Maybe next year I will recruit an undergraduate researcher to look into the parasite issue.

17 day old goshawk nestlings from nest #3 w/ Black Flies

We have also observed adult male goshawks in three territories where our protocol has yet to find an occupied nest. Of course, it is possible that we have just not found the nest; we will continue to monitor those areas. In another territory a sub-adult female was on a nest, usually a sign of a shortage of females. Is there a shortage of females in the area? A sub-adult female breeding and possibly three bachelor males? Is the blood parasite killing offspring? Is this a healthy population? So many questions... For now mine are focused on the population structure and the prey influences on this equation.

Nest Cameras

One of our main tasks are the installation of nest cameras. These cameras will enable a quantification of the prey consumed. They will also provide insight into other interesting behavioral aspects of a nestling's life. But first the cameras have to get up the tree.

Climbing nest tree #3 to install camera.

One of the most unsettling things for me about tree climbing is working over the branches. The harness is set up with two slings around the tree. When you reach a branch you put the second sling over the top and release the first sling. That release step, removing the only protection you have been using to hold on the tree, takes very careful consideration. The new sling must be attached and locked correctly. With eight to ten sling swaps per climb, there is ample opportunity for mistakes. I remain as focused as I can, take my time, and double check every move.

The first look into the nest.

Holding cable in my teeth while aligning camera. Note black flies on nestlings.

I align the camera in the tree while Lauren looks at the monitor below and provides instructions on how to adjust the alignment. The camera units are set up so that batteries and memory cards/tapes can be exchanged 200 feet away so that subsequent disturbance to the nest is minimized.

Double checking the configuration and video feed when back on the ground.

The focus, effort, and adrenaline take its toll. I am on a high for about an hour, then I want to nap away the afternoon...

It will take months to sort through the video I am capturing, but it doesn't take long to find interesting behavior. At age 4 days the nestlings begin to defecate over the rim of the nest. This 15 second video of a 10 to 13 day old nestling provides a great example.

But as I mentioned earlier,my focus is on prey. Here is a 25 day old goshawk walking around the nest then eating a chipmunk (meal starts about 40 seconds in).

Nature does know how to deliver surprises. Once I put my head over the rim of nest #2, this is what I saw.

Dead Nestling in nest #2.

The cause of death is not determinable. Sometimes nestlings are killed by their nest mates to decrease competition for food, but there was no sign of that here. Maybe starvation? The clutches are smaller this year than in previous studies, so resources could be more scarce. Unfortunately the dead nestling was gone before the camera was fully operational (12 hours later). We therefore do not know if the female removed it or if it was eaten. Few resources are wasted in nature.

The cameras are complicated technology for the outdoors. While they provide tremendous insight, they have been the source of frustration and have not worked out as well as planned. I had originally planned six cameras. Due to the battery recharge challenges, I scaled that back to 5 cameras. Two of these are analog units that only record for a day and a half at a time. I replace these batteries every two days. I have three digital units which can last a week on a battery charge. Unfortunately, one of these recorders died while operating in nest number one. I replaced it with my last available unit the day before I discovered a new candidate nest. I still have one analog unit, but this new territory is 2 hours each way by motorcycle. It would take far too much time to replace the battery every other day. So here I am with three cameras installed, each providing about 75% of the daylight hours. The TV monitors used to align the camera and configure the recorder has only worked on one of our three installs, requiring more followup to get the system fully functioning. I will defintiely be re-evaluating choices at the end of the season. For now, I hope the three units keep working for a few more weeks.

Scalped

Before heading into the field I have heard many stories of individuals getting attacked by goshawks. This usually occurs when 50 meters or closer to the nest tree. After my first encounters I was beginning to believe that these stories were overly exaggerated. While climbing my first tree, the two adults protested and flew toward us, but only brushed me with a wing twice. During the second camera installation, the female perched nearby, never even bothered to leave her perch. She didn't issue the first alarm call until I was three steps up the tree! On climb number 3, while the female made many flying approaches, no contact was ever made. What was all of the excitement about? Well, I would find out the hard way.

I was completing a prey survey in a new territory which had not yet been searched. Searching would be my task for the afternoon. I was 600m from where my information had told me the historic nest location would be. Just as I finish the survey a male goshawk issued the alarm call to my right. The female shot up out of the forest! I got the nest! I move in to find the tree and check on nestling status. The adults flew toward me while screaming their call. I ducked to the side, stayed close to trees, etc. I could see the nest and could see the evidence of nestlings (fecal marks on the ground). I quickly turned to retreat. Within moments the alarm calls ceased then wham!! my head gets knocked forward. I picked up the pace and got out of there. I touched my head... OUCH! Hmmm... Blood...

I like the full foot print of talons on the right.

The adults do get more aggressive as the nestlings get older. On Wednesday I reclimbed nest #1 to band the nestling. While I was only brushed twice during the first climb, the second climb produced a dozen direct hits from the female. She was able to hit me once just below the helmet to scratch the back of my neck! I will definitely turn up my collar for the next climb. The warnings from the ground crew are very important, "incoming!", so I am not in a critical climbing move when she's coming in.

Incoming!!!!!

Helmet ringer!

The Beginning of the End

The project is now six weeks complete, with only 2-3 weeks remaining. The end of the field season is no longer an abstract concept, but a huge boulder rolling down the hill. We constantly rearrange tasks to make them more efficient. We make decisions based largely on minimizing time. We hike double time through the sage to fit one more prey survey in before the 11:30am cutoff the protocol specifies. Right now, it looks like we will make it. Barely...

Other Observations

The other wildlife observations have taken a back seat to goshawks in recent weeks. Notable are many observations of moose including a few new moose calves. The bull elk are herded up and in full velvet. The mule deer are prevalent and the bucks are spectacular. More coyotes, badgers, beavers, and cougar tracks. Red-tailed Hawks, Turkey Vultures, Short-eared Owls, Golden Eagles, Northern Harriers, Cooper's Hawks, Sharp-shinned Hawks, etc. The South Hills are definitely a special place to have as a study area.

Volunteers

This session we had a number of volunteers join us in the field. Uri, Nicole, Kerry, Jeri, Cristen, Dave, Carol, Cathy, and Karyn all spent time hiking through the woods with Lauren and I, taking notes, and carrying gear. Uri had the honor of finding a nest which we had spent days looking for. Dave, Carol, Cathy, and Karyn all fixed us dinner on different evenings to try and keep us from withing away (I am down 6 pounds in 6 weeks!). It is great to have such excellent family, friends, and volunteers.

Lauren, field assistant Superstar! The next climb is hers!

Dave and Carol, excellent Idaho Bird Observatory volunteers. Thanks for Dinner!

Cathy, excellent volunteer, photographer, and cook!

Mmmm, Warbler for Lunch

2011-06-11T11:37:00.001-06:00

Local Cooper's Hawk preparing Yellow Warbler for lunch.

Cooper's Hawk plucking Yellow Warbler.

Cooper's Hawks in nest eating Yellow Warbler

The Tale of the Stolen Jacket!

2011-06-11T11:21:00.001-06:00

In my previous post I told the story of a Northern Goshawk stealing my jacket. Here is a slow motion helmet cam video of the incident. The green fleece jacket was placed over the nestling while I was installing a nest camera in the tree. This helps to protect the nestling from the elements and to reduce its stress. While I was setting up my rappel to come out of the tree, one of the adult goshawks flew by and took the jacket from the nest. A field volunteer ran through the forest and retrieved the jacket after it was dropped by the raptor.

In this slow motion video you can see the jacket as I am working with the climbing rope. Suddenly its gone! Look low and to the left in the frame and you will see the adult flying into the trees with the jacket. It makes total sense to attack the jacket as it was on top of their only nestling. It was a very cool experience.

The project is rolling now!

2011-06-10T10:32:00.002-06:00

As expected, we have become more and more busy as the new protocols come online and as access to new territories occur. Although at the end of week 4 we can still only access 13 of the original 23 historic territories I plan to work in. I am eagerly hoping that next week opens up new opportunities.

Lauren and I were joined for three days by another volunteer Michelle, a former student of mine. She provided excellent field support and likely learned a great deal. Dusty and Mike joined us in the field for the camera installation as well. I have a couple of other volunteers joining during the next few weeks and possibly for the session after that. Some are former students and others are friends considering a career in biology. It's great to have the extra help.

New Nests

The new week enabled access into five previously unvisited territories (due to snow and mud), bringing my total accessible territories to 13. This quickly delivered two new occupied nests, for a total of four. Lauren and Michelle discovered the first, and I discovered the second. On the nest that I discovered it looked as if the female was sitting very high on the nest. This can often mean that nestlings have hatched. As I watched a small white head popped out from under the female. Nestlings! The first observed of the season. Very cool! This would lead to this nest being the first to be installed with a nest camera (story below).

Newly discovered occupied goshawk nest.

Call Stations

One of the new techniques for this week is the use of broadcast call stations. This procedure consists of playing the goshawk alarm call and then listening for a response. This procedure is not used until the first of June as the goshawks don't generally respond until after the chicks have hatched. June 1st is the average hatching date in my area. Our first day using the new technique was productive as both Lauren and I had aggressive responses to the call backs. I had a female aggressive vocal response as she flew toward me calling. Lauren had an aggressive male response in another territory. Unfortunately, neither response has yet lead us to a new nest. We have yet to give up on these territories though. As we have the areas localized, if there is a nest, it could be close. Another aggressive female response later in the week did lead to new nest discovery (fifth of season).

Volunteer Michelle broadcasting goshawk alarm call.

Fifth nest of season, this one located in Lodgepole Pine.

Prey Surveys

A core premise of my thesis is the relationship between prey abundance and goshawk nest success. One of the mechanisms I hope to use in a series of prey surveys in each nesting territory. These prey surveys will be used to generate a general prey abundance measure of the territory which can be used for comparison between successful and unsuccessful nests. The method I chose to use is called distance sampling along line transects. Each historic goshawk territory has four 750m lines randomly placed within its bounds. For each round of surveys we will walk one of the 750m transects, noting any potential prey observed - Ground Squirrels, Chipmunks, Robins, Grouse, etc, and measuring the perpendicular distance from the transect with a laser rangefinder. These measures will be used to generate detection probabilities and ultimately estimate prey abundance for the each territory. I had hoped that I could do each round across all 23 territories within a period of three to four days. As mentioned earlier, I do not yet have access to many territories. Regardless, I chose to complete the first round on the 13 territories I did have access. New procedures often bring many new learnings. The first challenge was the two inches of new snow on the ground the morning that we began. I walked 500 meters before seeing my first potential prey item. This was in an occupied territory as well! Learning number two is that 30 minutes after sunrise, does not mean the sun has risen on the territory. As a result, I have shifted the surveys later in the morning - 30 minutes after sunrise in the territory, not what the calendar says. It is way too early to look at the data, but I can say there was no initial obvious correlation. We will initiate the second round of surveys next week on the 13 territories and hopefully the first round in some new areas.

Nest Cameras

The story of the week is definitely the installation of the first nest camera. This was scheduled for Wednesday as the nestlings were estimated to be 8-10 days old. A lot of coordination was required to get the gear in place, invite my climbing coach down to the area, and to align our schedule around the weather so as to minimize exposure to the nestlings during the camera installation. It looked like it could all come together.

The proposed climb! - Not a very big tree!

We staged the gear about 100m from the nest. We completed the last bit of training on the spot, then it was time to make a decision. We needed 2 hours of clear weather, at least no rain, to proceed. The fog was rolling in, but there was no immediate threat of precipitation. We made the decision to go. The four of us (myself, Lauren, Dusty [climbing coach], and Mike [Dusty's student]) all had our roles. I would climb, Dusty would coach, Lauren would belay if needed and coordinate the camera once I reached the nest. The camera is installed in the nest, but the recorder and battery are at the end of a 200 foot cable. This allows for remote battery and tape exchange without disturbing the nest again. Mike would take pictures, assist on demand, and yell a warning when a goshawk was about to take my head off! A very important task! We gathered the gear and moved toward the tree.

About 80m from the nest the male goshawk issued the alarm call! Dang! I had hoped he was miles away hunting. I would have to deal with two angry parents from the start. I approached the tree, rapped the sling around and left the ground. The female left the nest and the clock was started. We hoped to be out of the territory within an hour.

Dusty coaching me up the tree.

It was hard not to just watch in admiration as the parents flew through the forest heading to attack me, but I had a job to do. Up I went.

Approaching the nest bowl.

This tree proved much more difficult than the training tree. I guess the training isn't over yet. The hardest move is getting around the nest. I planted an anchor at the base and attempted to move up and over the side. I worked up over the lip and FALL #1! Yikes! A dead limb broke... Nothing gets your attention like taking a fall 30+ feet above the ground. I hugged the tree and tried to recover my senses and my wind. This is hard work! The clock was ticking, but I forced myself to relax and take my time. I worked the move again... FALL #2! Wow, getting tired. Focus... I rapped the limb again and wrenched myself up over the rim and into another anchor. I was there and ready to work. What?!? Only one nestling. I had expected three or four. Five was not out of the question. Only one. It was big, not 8-10 days old, but 14-17 days old. I guess measuring age by the amount of fecal material on the nest rim doesn't work when there is only one nestling. I placed my fleece jacket over the nestling to protect it from exposure and help it to relax. Not that it would relax with the parents' alarm calls flying by my head.

I hoisted the camera up and began the installation. On the ground the monitor failed. Dang, I would have to align the camera on sight alone. It was done.

As I was setting up my rappel, one of the adults flew over the nest and snatched my fleece coat covering the nestling! Off through the woods it went! Unbelievable! Mike went running after and eventually returned with the jacket. I set up my rappel and got out of the tree. We quickly grabbed the gear and retreated as far as possible. Without the monitor, I cannot ensure the camera settings are correct. I hit record and we left. High def, low def, motion activated or always on. Who knows... We get what we get... I will find out Monday...

I was cooked. Exhausted from the stress and the effort to climb the tree, I needed a break, but there was still work to do. We existed the territory in 55 minutes - ahead of my time allotment. It seemed like a blur of confusion and chaos, but even with the falls and equipment malfunction, we got our job done and mostly right. The camera monitor was the only real problem. It's a great team I work with! It is an honor to work with them.

Other Challenges

Field work is always presenting new challenges. The setback of the week was the broken motorcycle. After finding the nest with nestlings, Lauren volunteered to perform prey surveys in that area in the hopes of stopping by the nest and seeing the nestlings. Little did she know when she volunteered, that it would be a balmy 26 degrees in the morning and the motorcycle was the only vehicle to get there! She was undeterred. Adding to the challenges was a couple of new inches of snow on the ground. She headed off for the slippery cold ride as Michelle and I climbed into the heated truck. Six hours later when our work was done, we would learn of Lauren's fate. The roads were very snowy and slippery which quickly turned into wet and slippery after the sun came up. Not the ideal conditions for a motorcycle. The bike unavoidably slipped into a rut and the chain came off. Six miles from camp on a dead end road. What a beautiful morning for a walk! While Michelle and I were performing prey surveys and call stations, Lauren was hiking the muddy road back to camp. Just before arriving back at camp, the first person she saw was the man, Rick, from the neighboring camp who Lauren had made friends with the night before. He offered to help, took her to the bike and got it back on the road. When we returned later in the day, Lauren was sleeping on the ground next to the bike in camp. Next on the agenda was a bike repair in Twin Falls! On Saturday I took it to the shop. Standard answer - sometime next week. I tried to politely reemphasize my urgency - it was a work bike and the only way I could get my study complete. Well, maybe they would get to it later in the day. Ok, I will wait. This was not the answer he was expecting. They decided to put it on the rack right then. About an hour and a half later, I was headed back into the hills! Thank you to Kevin at Adventure Motorsports!

The Week ahead

The week ahead brings much of the same, but on a larger scale. More nests to find, more prey surveys to do, and more cameras to install! Hopefully with access to new territories. It will be a busy, but wonderful time. For the next ten days we will have a second field assistant and possibly one or two other volunteers spending time in the field.

Other experiences

One of the things I love about field work, is you come across many different surprises and discoveries. Such as spooking up a deer or an elk while walking through the woods. I actually logged an elk at 60m during a prey transect! Ok, maybe a goshawk can't take an elk, but I wrote it down anyway. Lauren saw a Moose, and I had a Badger. Coyotes, Beavers, White-tailed Jackrabbits, you name it.

One of three Beavers working this pond.

Since we spend a lot of time looking for nests, we have a high probability of find them. To add to our five Northern Goshawk nests, we have found an occupied Red-tailed Hawk nest (with nestling), an occupied Cooper's Hawk nest, and an occupied Common Raven nest (with nestlings). The most surprising was the American Robin nest that I discovered when my face was about 2 feet away and the female Robin flushed from the nest! Scared the crap out of me!

American Robin Nest.

Another surprise was having a Northern Saw-whet Owl fly right by me mid-day and perch in a tree.

Northern Saw-whet Owl.

Unfortunately, one thing we are likely to see a lot more of is dead raptors. Once raptors fledge, their chance of survival greatly diminishes. Over 50% will likely die during the next 3 or 4 months. While not a raptor, this fledgling Raven didn't do so well.

Dead Common Raven Fledgling.

You can tell it is a fledgling as its feathers were still growing. An adult will only replace a few feathers at a time, whereas a fledgling will still be growing all of their feathers. This fledgling Long-eared Owl also met its fate. I found this right after watching an adult Long-eared Owl fly by.

Very dead Long-eared Owl Fledgling.

Yes, only a geeky biologist photographs the dead things he finds...

With that, I have a few days off an then its back to work. Prey surveys, nest cameras, new territories, it feels like a whole new project. I can't wait to get back out there!

Two weeks in, three weeks behind...

2011-05-27T16:31:00.001-06:00

Here's an update on the progress I have made during the second week of my field season. I have previously posted an introduction and summary of the first week. As you might be able to determine from the title, the field conditions continue to provide unexpected challenges. With that said, I am still optimistic looking forward as some early signs of spring are beginning to reveal themselves in the area.

The return to the study area for the second week was filled with optimism. Having seen a male goshawk in a particular territory and receiving some updated information on where the nest might be, we were excited to go find it. We first checked in on one of the previously discovered nests just to confirm that she was still incubating. She was! So we headed on our way. The road was snow covered, but looked doable. A couple of hundred meters down the road, we changed our minds... I tried to back out, but couldn't make it. We had to turn around. This is where it all went horribly wrong. The front end slid into the ditch. We were stuck.

Lapse of judgment!

The truck was equipped with two shovels (luckily), but the only other equipment we had was a floor jack (not so luckily). After working for 2 hours with these tools, we determined that better equipment was needed. We would walk back to the cabin and hope for the sheriff or forest service to come by in the next day or two. At least I had my motorcycle to get around. Good thing our territory was within hiking distance. Just after arriving at the cabin, the forest service enforcement officer (Kirby) stopped by! He took a look at our vehicle and said that he couldn't help. He suggested that we cover the Boise State door sticker with a University of Idaho door sticker and leave it there until the snow melted, which has to be within a few days... He did lend us a high rise jack (widow maker) before going on his way. Not wanting to ruin the entire day, I sent Lauren on to the territory while I worked on getting the truck out. Two hours later, it was free. I hiked down to join Lauren in the search. Hours later we had racked up 3 additional nests, but none of them occupied... It was a bust.

Next up, the Albion mountains! Its a pretty good drive out of the South Hills and in to the Albions. Luck was still not on our side. The first territory was high on a ridge across a raging stream. Just the night before, a flash flood had occurred wiping out half of the road and cutting a deep channel. The water was still raging and not offering us a safe crossing. We passed for the day and moved on. The next territory provided easier access, but when we found the nest tree it was not occupied. If this trend continues I will definitely be facing small sample size issues! We returned to the South Hills empty handed.

About mid-night we awoke to a banging noise outside. It appeared that someone was stuck in the Magic Mountain parking lot. There is a huge mud hole there. This would be the second vehicle in a week. Lauren suggested that we go see if they needed help. I wanted to make sure that we did not become over committed, but since we did have a radio that could reach law enforcement, we could offer that. As we walked down toward the vehicle we noticed the sheriff was already there. In fact, the sheriff was helping to pull the vehicle out. Hmm. The other vehicle was also a sheriff! This story was getting better!!!

Sheriff Kelly in mud hole being pulled by Sheriff Steve and ourselves.

We had previously met Sheriff Steve (pulling), but not Sheriff Kelly (stuck). Steve was happy to see us and the help we could provide. Kelly was a little less happy that the audience had expanded, but also welcomed our assistance. We returned for our truck and within ten minutes, he was free. I think this earned us a "Get out of jail free card." I am willing to bet that this isn't that last vehicle that will be stuck in the South Hills this spring.

Our new friends - Steve and Kelly.

Wednesday - two new territories to cover. Lauren was signed up for a ten mile round trip hike over the snow ridge to check on one of our occupied nests and to search a new territory. I had a 1.5 hour each way motorcycle ride to my territory (had to ride out of and around the South Hills). This could possibly provide access to another territory as well. The first territory was beautiful - a mix of Aspen and Lodgepole Pine. I would see a Wild Turkey, a White-tailed Jackrabbit, a Coyote, lots of woodpeckers, Mountain Bluebirds, Red-tailed Hawks, Ravens and an unbelievable number of Ruby-crowned Kinglets singing to their hearts content. Unfortunately, I would not find a goshawk nest. I tried to get to the second site another four miles further up, but snow drifts once again prevented my passage. Lauren would also come up empty on the day for her territory. Ouch.

Typical South Hills Goshawk Territory - Aspen, Lodgepole Pine, Sub-alpine Fir, Sage.

Lodgepole Pine Maze.

The news wouldn't get any better on Thursday. Our plan was to drive around the west side of the forest and camp there to access five potential sites. These sites are only 10 miles from our cabin, but the snow prevents vehicle access over the ridge. We awoke to three new inches of snow on the ground! When will it stop?!? Once we hit the gravel roads on the west side, we knew we might be in trouble. They were saturated and very muddy. As we drove higher and higher, the conditions worsened until we decided not to risk going further. We sat there in frustration for 30 minutes before heading back out of the hills and on toward home. Defeated for the week... No new nest sites... Very little progress in our searches... Frustration...

I have pondered a few of my learnings so far. The most obvious choice is to start the season later next year. Of course, next year the snow may melt weeks earlier (average melt is three weeks earlier than this year). A second thought is to design a project that is less dependent upon timing. Utilizing nest cameras to quantify prey consumed requires early access. The first cameras could be installed as early as next week. My other methods and questions do not require as early access. A third point has been the low quality of the historic data on which I depend. Some of the coordinates for the nest sites I have are in the middle of a sagebrush field. Clearly not even close to a "nest tree". Next year I will of course have much higher quality and more recent nest site data - mine. Some literature speaks to the high degree of nest site fidelity, but I have received word from other researchers with contradictory data. A review of the past research also notes that a large number of nests are blown out of trees and some of the historic trees are no longer standing. I expect that another limiting factor is our ability to detect the nest. Nests located in Aspen are fairly easy to see and locate, especially now before the leaves come in. Nests in Lodgepole Pine however are much less conspicuous. I imagine that our skills will improve with time. One of the challenges within the South Hills is the very large amount of parasitic mistletoe. Each mistletoe ball looks like a nest structure from a distance. Unlike many other raptors, Goshawks build nests below the canopy which is where the mistletoe also grows.Mistletoe in Sub-alpine Fir is very easy to write off, but in Douglas Fir or Lodgepole Pine it requires closer inspection.

Mistletoe.

We have a big week ahead. We will start broadcasting goshawk calls which will greatly improve detectability. Before the first of June broadcasts are discouraged due to the stress placed on incubating birds and the fact that they are less responsive before the eggs hatch. We will return to each site where we failed to detect a nest and use the broadcast search protocol. We will also begin our prey surveys. These surveys involve hiking a 750 meter transect in each territory and counting each potential prey species - ground squirrels, chipmunks, jackrabbits, and many bird species. Using a laser rangefinder we will measure the perpendicular distance from the transect to each individual mammal or bird. The resulting values, along with several repeat transects, will be used in a statistical procedure to produce a prey abundance estimate for each territory. These prey abundance estimates will then be compared between territories as predictors for occupancy and nest productivity. Lastly, I HOPE HOPE HOPE for access to the rest of my study area! If this occurs we will have more work to do than we can possibly complete! That would be awesome!

Great Horned Owl v Snake

2011-05-21T10:26:00.001-06:00

While waiting for a prey delivery to the Cooper's Hawk nest, I watched a Great Horned Owl dive on a snake. I repositioned to get a better angle and caught this in flight. The snake looks to me to be a Racer.

Great Horned Owl with snake (Racer?).

First week starts with a bang, ends in snowy frustration but renewed optimism

2011-05-19T10:48:00.001-06:00

The first week of my master's thesis field season studying Northern Goshawks was a mixture of stress and anxiety, ecstatic discoveries, frustration, and disappointment. A year's worth of planning all came together for a successful week that fell short of expectations. I was not surprised by this. Last week I posted a quote predicting that my plans would undergo significant challenges and it indeed came true. The good news is that we did make progress (discovered two occupied goshawk nests), we learned along the way, gained renewed confidence in my field methods, and we have a renewed plan of attack for next week.

My study area is in the South Hills, a portion of the Sawtooth National Forest located south of Twin Fall near the Idaho/Nevada border. Since the study is partially funded by the Sawtooth National Forest, they have generously provided us lodging in the small cabin picture below located on Rock Creek in the South Hills. My field assistant Lauren, myself, and other occasional volunteers will be staying there. It sure was nice the first week as the outside temperature dipped to 16 degrees and snow was falling much of the time.

Our home for the next eight weeks.

For the first few days Lauren and I were joined by Karyn (my wife), by Jay (Idaho Bird Observatory Research Director and my thesis committee chair), and Heidi (Idaho Bird Observatory researcher and BSU Graduate Student). After our arrival in the South Hills and an evening cleaning the cabin, which had been closed up all winter and possibly for a few years, we headed out on the first morning to find our first goshawk nest. I had been given rough coordinates for a number of historic goshawk nest locations and we chose one which looked to be easily accessible.

Heidi, Jay, Me, and Lauren navigating through our first territory.

While it snowed much of the night, the first morning was clear and cold. The cold crusty snow enabled us to hike without snowshoes. We worked our way toward the expected nest location. Once we were within 100 meters of the assumed location, we split up and began the detailed search. Just one minute after splitting up I looked up and right there in front of me was the nest! It was occupied! I can honestly say that I haven't felt that excited in some time. It was such a rush. Three years of preparation for this new career, one year of planning on this project, and less than one hour in the field and I was staring into an occupied nest! I used hand signals to tell the others I had found the nest!

My first view of the nest tree in front of me!

Female Northern Goshawk on the nest.

Wow, this was easy. Only 24 other historic territories to go. As you might expect, it doesn't always work like this. We moved on to the next territory. This involved a one mile hike on snow, occasionally post-holing, followed by a thorough search of the area. With five people for two hours we were not able to find a nest. Finding this particular nest in this territory was supposed to be easy. We decided to move on as we could ask for more specific directions later from individuals who had been to the nest. That afternoon, in a third territory, we again failed to find the historic nest. Some of these nests haven't been looked at in the past eight years. The original GPS coordinates could be as much as 200 meters off. This might not sound like that great a distance, but in dense forest, post-holing in snow, the effort to find a single nest in a single tree is definitely considerable.

Discussing search strategy with Heidi.

A new days brought new nest searches. Unable to cross the ridge due to deep snow we drove for 2 hours around the outside of the forest to gain access to the west side of the mountain range. On the drive we saw a male goshawk perched on the ridge. We bailed out of the truck to observe and mark the location.

Me, Laruen, Heidi, and Jay observing goshawk on the ridge.

Our first search of the morning was rewarded with our second occupied nest! Jay discovered this one. Surprisingly, this nest was occupied by a sub-adult female (one year old bird). Sub-adult females are able to reproduce, although sub-adult males usually are not fertile. I am definitely liking this morning success. Should we just take the afternoons off?

In second territory search on the west side of the mountain we were able to find the historic nest, but unfortunately it was not occupied.

View over territory.

Lauren scanning for nests.

Jay and I overlooking territory as the clouds roll in.

The lack of an occupied nest caused some lapse of focus as Lauren and Heidi started inspecting the lichens on the rock, which was also covered in Marmot scat. Do you think a goshawk could eat a marmot? Hmm.

Fungus nerds (Lauren and Heidi) inspecting the lichens.

The storm hit as we headed back to the cabin for a meeting with the wildlife biologist from the forest service. In fact, I had driven this road three days in a row and it had snowed there every day.

Snowing in Rock Creek.

On the third day it was left to Karyn, Lauren, and I as Jay and Heidi had their own projects to get on to. With new information we returned to a territory from the first day. The three of us systematically searched the area again for 2.5 hours. We did find an unoccupied nest, but it mostly likely belonged to a Red-tailed Hawk as it was near the top of the tree and open where goshawks prefer to nest under the canopy.

Lauren and I inspecting coordinates on the GPS.

A few days before we had seen an adult male goshawk fly from a stand of trees about 700 meters from our documented nest location. Karyn suggested that we go search there. I said no as we have a search protocol which would eventually take us there, but we first had to find the historic nest. As the fog came in and the snow decreased visibility we headed in for the morning. I would later receive updated information from the forest service that in recent years the nest has been located in that very stand of trees that Karyn proposed searching. I guess Karyn has earned a significant number of "I told you so's". We will head there first thing next week!

With limited road access, the amount of snow on the ground, and a forecast of more snow in coming days, we made the decision to abandon our work for the rest of the week. We will return on Monday, hopefully to better access and higher productivity. This first week was filled with the excitement of finding the nests, with frustration of only being able to access about 1/4 of the study area, and relief that I believe my field methods in general are going to work. I am now excited to return to the area on Monday morning.

With the amount of time we spend in the field, we are able to observe other wildlife as well. One species of unique interest in the South Hills is the South Hills Crossbill. This bird is a sub-species of the migratory Red Crossbill which has taken up permanent residence in the South Hills. There it has evolved a unique morphology which has resulted in it being proposed as its own species.

Male South Hills Crossbill.

The South Hills lack tree squirrels, so the South Hills Crossbill has taken over the role of the pre-disersal seed predator of Lodgepole Pine. As a result the Lodgepole Pine has developed a unique defense in its cone structure to protect against the Crossbill seed predation instead of the usual squirrel seed predation. In the evolutionary arms race, the Crossbill has in turn developed a unique bill structure to overcome these new defensive mechanisms. This has driven the bill structure of the South Hills Crossbill to be different from the standard Red Crossbill. These birds are abundant and easy to see in the South Hills. Interesting stuff!

Male Northern Harrier.

Short-eared Owl.

Very awkward looking Sandhill Crane on a nest.

We have seen and heard many other bird species and have watched the increased emergence of the Belding's Ground Squirrel which are key prey items for the Northern Goshawk. I look forward to our return to the field early next week.

The Study Begins

2011-05-14T07:45:00.002-06:00

After a year of proposal writing, planning, and presenting, the first field season of my Master's study in Raptor Biology is about to begin. Yesterday I finished the spring semester of my classes and tomorrow I will be heading for the hills, the South Hills that is. For the next 8 to 9 weeks my field assistant and I, along with other volunteers, will be performing a range of field studies all pertaining to my study species, the Northern Goshawk. The purpose of my study is briefly explained in my project abstract.

ABSTRACT

Forest structure has a profound impact on the species communities which live within its boundaries. The size and shape of a forest plot, the unique plant composition, and the proximity of the forest plot to other plots are among the factors influencing the species composition and dynamics over time. Anthropogenic impacts, both direct and indirect, can disrupt or accelerate the dynamic processes within a forest plot further shifting the species composition. Understanding how species utilize naturally fragmented habitat and how they respond to changes within that habitat can provide greater insight into their ecology and help prioritize management decisions to aid in conservation. The Minidoka Ranger District of the Sawtooth National Forest of Idaho, with its discreet forest segments and unique flora and fauna, presents unique challenges to sensitive species such as Northern Goshawks. The naturally fragmented forest structure found in the Minidoka Ranger District exhibits the constraints of island biogeography. The top identified food source of Northern Goshawks worldwide, tree squirrels of genera Sciurus and Tamiasciurus, are naturally absent from these forest islands. Additionally the Aspen forests upon which the Northern Goshawks locally depend are under threat from historic fire suppression practices and global climate change. I propose a multi-year thesis project to explore the breeding health of the local Northern Goshawk population by studying territory occupancy rates, breeding success, and fledgling sex-ratios relative to habitat quality, territorial prey abundance and predicted forest structural changes. The results will provide forest managers with information on the state of the Northern Goshawk population within the Minidoka Ranger District and the most significant factors affecting successful breeding within the population.

Much of our field time will be spent searching for Northern Goshawk nests. We will be visiting historic nests and checking for occupancy and systematically searching for new nests. We will be installing a total of six nest cameras to quantify what they are eating. Yes, tree climbing skills are critical. For each territory we will perform prey surveys every two weeks, counting every potential prey species observed. We will monitor the nest success and productivity, then lastly document the habitat structure of the nest stand.

All of this collected data will be processed over the next six months to answer the key research questions mentioned in the abstract. During this time, adjustments to the field processes will be developed for my second field season next year, when I will be doing it all over again.

As we head out to start this field season, a few challenges await. First and foremost is that the snowpack is two weeks behind average in melting. This follows many years of it melting earlier than average. The result is that there is still 36 inches of snow across much of the study area. We will be using snowshoes to start the season and some territories will just not be accessible. I am worried that previous studies have shown a very low nest occupancy rate in heavy snow years. The snow wasn't as heavy this year (only 20% above normal), but stayed much longer (snow pack now is over 200% of normal). I have a detailed day by day plan for the first week, which is now moot due to snow. I haven't even set foot in the study area and my plans are already out the window. This reminds me of one of my favorite quotes:

"In preparing for battle I have always found that plans are useless, but planning is http://www.blogger.com/img/blank.gifindispensable". -Dwight D. Eisenhower

Lets hope my planning has enabled me to respond to these new challenges. And so I begin this journey with tremendous excitement and an open mind to let the season play out before me. What I do know for sure is that it will be a fantastic adventure. I will try to provide updates, although they will likely be brief.

Project is funded in part by a Challenge Cost Share agreement with the USDA Forest Service, the Mike Madder's Field Research Award, and Boise State University Raptor Research Center.

A Hootless Hike

2011-04-23T15:55:00.001-06:00

After 8 weeks of surveying for Flammulated Owls in 2010 (summaries: The Life of a Field Biologist, Meeting the Locals, Back in the Wilds, Drizzle, Rain, and Mud, New Players, and Bloaticus [this last one is the best]), I wasn't sure if I would have an owl job again. While I greatly enjoyed the time spent in wild places listening to wild and sometimes elusive birds, the disruption of my other life activities was fairly high. Regardless, the opportunity once again arose and I answered the call.

The Idaho Bird Observatory, where I perform my research, where I sometimes work, sometimes volunteer, and sometimes receive sponsorship support, received a last minute contract to perform Great Gray Owl and Northern Goshawk surveys for an exploratory mining operation. They needed experienced biologists which were available on short notice, could get the job done with little supervision, and were crazy enough to snowshoe through the woods at night for hours on end. I got the call. Through a temporary (permanent??) lapse of judgement, I agreed to participate!

Great Gray Owl (Strix nebulosa)(NOT in the study area).

My field partner would be none other than Lauren, who is also my upcoming field assistant on my Northern Goshawk Thesis research. These owl surveys would provide a good training and team-building opportunity before my project begins just three weeks from now.

The first weekend out we had hoped to preview the area and complete one of the transects. The preview was successful - conclusion: there is lots and lots of snow. The snotel site on the edge of the study area reports 93 inches to be exact. This would require some adjustment in the plans. We snowshoed in 3 miles to the first of 17 transect points, arriving about 45 minutes later than we had planned. Traveling over the crusty snow and up steep slopes took more effort than we had planned. Some areas were just too steep to ascend, so we had to work around the area. Upon arriving at the first point, it started to rain. The protocol can be completed in a light drizzle, but nothing heavier. We completed the survey at this point with no detections and started moving on toward the next point. The rain steadily increased as the clouds lowered to surround us. It was clear that this was not a passing issue. We called off the remainder of the night and headed back toward the car. We were right - it rained and rained and rained. It rained all of the way home and well into the next day.

Another weekend, another attempt. We planned a different route, expecting to climb a ridge and begin the surveys at the highest point and work our way down through the night. This required us to begin hiking 1.5 hours earlier, allowing 3.5 hours to reach the first point. The snow was lighter on the lower elevations allowing us to hike without showshoes for the first 1.5 miles. The weather was clear and beautiful with little wind!

Lauren near the ridge over our study area.

Me on the ridge with beautiful views overlooking our study area.

The hike up the ridge was spectacular, but a great deal of work. There wasn't a ton of wildlife on the hike, but we did see Northern Flickers, Steller's Jays, Mountain Chickadees, a Red-tailed Hawk and a Turkey Vulture. The Vulture was hanging out near a dead skunk that we found on the trail.

Dead Skunk (Mephitis mephitis).

On our trip back down the mountain hours later, it would appear the vulture got its fill of the skunk.

The owl surveys begin 1 hour before sunset. At our third survey point of the night, the sun was just setting through the trees. A great finish to the day and start to a long night.

Sunset from our third survey point.

The routine of navigating to a point, extracting gear from your pack, executing the survey, packing up, and moving on quickly becomes routine. A few points from the end, we realized how cold it was getting when the water in my bottle was frozen. Steady showshoeing with brief (5 minute) stops kept us plenty warm so not to notice the cold. After completing 16 survey points, it was time for the 4 mile hike back to the car. By this time the snow crust was firmly frozen allowing us to remove the snowshoes and hike on top of the snow, increasing our speed. We arrived at the car about 1:15 for our 2 hour drive back to Boise. The net result: Transect A is complete with no owl detections. We logged 11.9 miles of hiking/showshoeing and approximately 4000 vertical feet of climbing. Ouch. The stairs are very painful today...

Next week we get to do it again!

Northern Flicker

2011-04-23T12:31:00.001-06:00

Northern Flicker. Hull's Gulch, Boise, Idaho.

White-crowned Sparrow

2011-04-23T12:29:00.000-06:00

White-crowned Sparrow. Hull's Gulch, Boise, Idaho.

Hull's Gulch Great Horned Owls

2011-04-10T10:57:00.000-06:00

The local Great Horned Owls have nested in the sand cliffs for at least 6 years (years that I have been watching). They have successfully fledged at least 3 young every year, 4 young on many years. They have 4 chicks this year.

Great Horned Owl.

Western Screech-owl

2011-04-10T10:52:00.000-06:00

Western Screech-Owl. Quinn Ponds, Boise, Idaho.

American Kestrel v Red-tailed Hawk

2011-04-08T16:58:00.001-06:00

American Kestrel and Red-tailed Hawk

Sushi

2011-04-08T16:52:00.001-06:00

Clark's Grebes sharing lunch.

Clark's Grebes. Lake Lowell.

Where has Chivalry gone?

2011-03-31T13:46:00.000-06:00

What a beautiful day for a quick bird walk through our favorite local birding haunt, the Hull's Gulch Nature Reserve. With spring weather abound, there was a great deal of bird action to observe - two owl species, Red-tailed Hawks, Cooper's Hawks, American Kestrel's and tons of Waxwings including both Cedar and Bohemian. Here are some highlights.

Dictionary.com defines chivalry as "the sum of the ideal qualifications of a knight, including courtesy, generosity, valor, and dexterity in arms." We had the opportunity to observe the chivalry of the local male Cooper's Hawk, but also to observe its limits. Upon approaching the nesting area, I quickly spied the male Cooper's Hawk bullet like dive across the road and into the Sagebrush. He arose from the disturbance to proclaim his adept skill and "dexterity of arms", for he had successfully killed a large vole (Montane vole?). Apparently "modesty" is not one of the requirements. From there he did what any chivalrous male should do during the breeding season by quickly and "generously" delivering it to his mate! She was apparently pleased and immediately began to consume the catch.

Female Cooper's Hawk with vole.

This is when the "courtesy" of relationship started to fade. She had only eaten two bites when he mounted her and mated with her. Apparently dinner first only applies to the delivery and not the consumption! He went to perch nearby and watch as she ate. When about half of the meal was consumed, he once again mounted her for mating. "Courtesy" was further compromised along with "generosity" when he immediately after mating the second time, grabbed the remaining food and flew to his own perch. His apparent naive view of the world somehow included the misconception that some of the food should be his. This was not to be. The female immediately flew over and took the prize back. The male flew off empty handed.

Male American Kestrel.

At the upper pond we had the opportunity to watch the two Belted Kingfishers building their nest. They were chattering about their business flying in and out of the nest hole. A remarkably large number of American Kestrels were flying about. At least 6 individuals were seen within a half mile. We have observed them flying in and out of different nest holes in the sand cliffs in the general area where the Great Horned Owls nest. Speaking of the Great Horned Owls, we were able to watch the female feeding at least one owlet. They are deep in a dark hole so we could not tell how many chicks were present, but we look forward to when they move out onto the ledge.

Male American Kestrel.

Hull's Gulch Reserve is a great place for owls. The Great Horned Owls have nested there for years. Earlier this year we saw a Northern Saw-whet Owl in the area and later heard them near the sand cliffs as well. The photo below was taken in February.

Northern Saw-whet Owl (picture taken in February).

For the past month, every time we have been in the area we have been able to find either one or two Western Screech-owls. Lately only one. Maybe they too have a nest nearby.

Western Screech-owl.

One of my favorite non-raptor birds are waxwings. Hull's Gulch Reserve is often home to flocks of waxwings, mostly Cedar Waxwings.

Over 100 Cedar Waxwings with at least 7 Bohemian Waxwings.

I have searched the flocks for weeks hoping to find a Bohemian Waxwing mixed in. Waxwings often hang out in mixed flocks. The Bohemians tend to migrate north and thus are less likely to be seen once spring starts. I had not yet seen them this year and was thinking they were probably all gone. But close analysis of this flock showed at least seven Bohemians mixed in. If you look closely in the upper right and middle left you can see two Bohemians amongst the Cedar waxwings. The Bohemians are larger, have a richer rufous color around the face and vent, and lack yellow.

Waxwings, mostly Cedar but some Bohemian.

Waxwings are fun to photograph as their flocking behavior often has them returning to the same place. If you watch their behavior closely, you can determine where they are likely to go to get water, then set up and wait.

Cedar Waxwings.

Cedar Waxwing.

Cedar Waxwings.

The Northern Flickers were also getting in the mood of spring. We could here them drumming some distance away. After each drumming by this pair, another would raise a protest from 100 meters away. I love spring!

Northern Flickers.

Accipiter cooperii

2011-03-13T08:29:00.001-06:00

What a beautiful near-Spring day in Boise. Karyn and I headed out to our local birding trail to see what we could see. Hull's Gulch Preserve is our favorite hotspot for its local wildlife diversity, but also because it is a nice 3-4 mile hike from our house. Saturday would be a spectacular day out there. While we would see many species, the highlight were clearly the bird courting each other in this early mating season. A pair of Belted Kingfishers appeared to be searching for nest sites and were staying in close proximity to each other, chattering non-stop. American Kestrels were performing display flights at numerous locations. We found a pair of Western Screech-Owls snuggled side by side. It was one big dating frenzy. Of course, the season as long since passed for the Great Horned Owls as the female incubates her eggs under the watchful eye of the male. But the highlight of the day would come from the medium sized Accipiter hawks - the Cooper's Hawks.

Cooper's hawks are the smaller cousin of my study species the Northern Goshawk. They are a forest raptor capable of maneuvering quickly through reasonably dense forest structure. A few years back, we discovered a new nest within the Hull's Gulch Preserve, and they have nested there ever since.

Juvenile Cooper's Hawk

Our first discovery consisted of two juvenile Cooper's Hawks near the lower pond. The juveniles have very different markings than the adults as you can easily see in these photos.

Juvenile Cooper's Hawk

For a few weeks now we have usually been able to find the adults near their old nest location. Today would be no exception. We found both the male and female hanging out together.

Male Cooper's Hawk

Female Cooper's Hawk

I started to walk away to look for other birds as I heard the two calling to each other. I turned and raised the camera to see them mating.

Mating Cooper's Hawks

After the two regained their composure, the male went to work to continue building the nest. This is a new nest this year, not far from the old nest. It appears to be a much better location, although probably closer to human disturbance.

Male in new nest.

We watched as he repetitively flew out to gather nesting material and return it to the nest. He was collecting a mixture of nesting material from different locations, sometimes flying to the ground and sometimes to nearby trees. Some twigs were fresh branches that he broke off, others were dead branches on the ground.

Male Cooper's Hawk returning to the nest.

Male Cooper's Hawk leaving nest.

Cooper's Hawk returning to nest.

Male Cooper's Hawk in nest.

Cooper's Hawk in nest.

Ruined in Belize

2011-02-27T19:51:00.001-07:00

This is the fourth post in a series based on Karyn and I's trip in early January with two birder/biology friends to Belize. We have been back for more than six weeks now, so it is about time I finish our blog posts! This post is focused on Mayan ruins we visited while in Belize. The previous posts included a general overview of the trip - The Pursuit of Wild in Belize - a post focused on - The Raptors of Belize - and one focused on - The Water Birds of Belize.

Traveling to Belize to see the Mayan ruins has been on our list for some time. A number of years ago we flew through Honduras on our way to Roatan. At that point the seed was set. Well, we finally fulfilled this quest. After spending time on the cayes and in the lower elevations of Belize, we ventured on to San Ignacio for our home base of ruin exploration.

The first ruin on our agenda was Caracol. According to Wikipedia, Caracol is believed to have been first inhabited around 1200BCE and remained inhabited until 900CE. It is believed to have had a population over 120,000 people! Of course we didn't see the entire city! (click any photo to enlarge)

Caracol. Caana Temple.

The road to Caracol is 60 miles of rough dirt road, although not as rough as we were expecting. Half way to the site, there is a convey meeting spot where a military escort is provided to the site. Apparently a number of years ago there were some bandits which kidnapped some tourists. We found out in town that the escort was optional, so we left early to arrive at the site about 1.5 hours before anyone else. The birding here was fantastic, but even more so were the temples. The first temple was the Caana temple, still one of the largest man made structures in Belize..

Caracol. Caana Temple.

The climb up the front steps was steep, but the view of the surrounding forest was spectacular. I was surprised how good of shape the temple was in, being thousands of years old.

Caracol. View from half way up Caana Temple.

Caracol. View from Caana Temple.

Caracol. Design on structure opposite Caana Temple.

Caracol. Jay, Heidi, and Karyn descending from Caana Temple.

The Main Caracol center consists of three large sections. It is estimated that thousands of structures exist. The Caana temple is in section B. From there we walked on toward section A. This section consisted of a four sided amphitheater.

Caracol. I am approaching 'A' complex.

Caracol. Designs within 'A' Complex.

When I first entered the quad, I saw an Agouti foraging around the edge. An Agouti is a very large rodent and one of the few mammals we saw there.

Caracol. 'A' Complex.

We continued to search for birds in the area, successfully finding a number of new birds for the trip. After lunch we wanted to take another tour of the area, but the guy with the gun made a persuasive argument. If something did happen, he would be responsible and the tourism industry for his country would pay the price. While the convoy is optional, staying at the site was not. We reluctantly headed back toward town with the others.

Next up was El Pilar. El Pilar provided a large contrast with Caracol. First, it has not been fully excavated. It is intentionally left buried for preservation reasons. As the guidebook says, it requires more imagination. In addition, El Pilar is believed to be more of a meeting center or trading center than a ruling center. We only saw a few other people there all day. The birding was spectacular including Blue-crowned Mot-mots, Puffbirds, and the elusive Tody Mot-mot! The road into the site was also excellent for birds.

El Pilar. Building foundation.

El Pilar. Overgrown entrance to building.

El Pilar. Buried building.

El Pilar. Partially excavated building.

The last ruin on our itinerary was Cahal Pech. This translates into land of the ticks. Apparently when it was being excavated, cattle was ranging in the area as were a large quantity of blood sucking ticks. Luckily, we didn't find any. This ruin is located right in San Ignacio, so we checked it out one night before going to dinner. We had heard about it from our hosts at Cockscomb. It was their favorite site for spiritual reason. It too was interesting as it had many more internal structures than we observed at the other locations. It seemed much more modern, although it is believed to be older than either El Pilar or Caracol.

Cahal Pech.

Cahal Pech. Heidi in a doorway.

The ruins were definitely one of the highlights of the trip. Living in an area where most history is measured in the hundreds of years, it's amazing to think about something that is thousands of years old. Each of the three sites provided its own unique views into this ancient history. They were each special places!

Gyrfalcons, Ptarmigan, Peregrines and Sakers.

2011-02-04T16:20:00.002-07:00

This week, thanks to The Peregrine Fund, Boise State University is hosting an international conference on Gyrfalcons and Ptarmigan in a Changing World. As a graduate student in Raptor Biology and a volunteer for the conference, I received complimentary registration to attend. My schedule allowed me to attend roughly 2/3 of the proceedings. It was an excellent event!

As I have reported on other conferences I have attended, this conference too was filled with rich information stuffed into 15-20 minute segments. There was barely enough time to think through one presentation before the next one began. Here is the briefest of summaries on many of the presentations. At the end I will summarize some of my most important insights from the conference.

The conference began with a keynote evening presentation on Polar Bears and climate change that was open to the public. It might seem like a unusual choice, but many of the climate issues facing the Polar Bear are also facing other arctic breeders such as Gyrfalcons and Ptarmigan. In some cases the linkages are more direct than just weather. Arctic cod play a role in both food chains. Arctic cod is tied to sea ice. The Ringed Seals eat the cod, and Polar Bears eat the seals. Some of the Gyrfalcon prey, such as sea birds, are also dependent upon the cod. As the ice retreats, the cod retreats, and the seals retreat. Polar Bears lose and sea birds lose. In some cases, this propagates up the food chain to Gyrfalcons. The keynote was a mixture of awesome photographs of the arctic and polar bears along with the harsh realities of climate science. The presenter finished off the discussion with his elements of hope. That hope sits with the possibility that we will cap CO2 emissions by 2020. If so, they predict polar bear populations will stabilize at a level well below today's population, but not at a critically low level. Not much to hold on to...

The sessions began on Tuesday morning with an welcome message by the Peregrine Fund, BSU Vice President of Research, and then Dr. Mark Fuller, head of the BSU Raptor Research center. Then the sessions began. First up was Mohammed Al Bowardi for a summary of Gyrfalcon's role in the history of Falconry in Arabia. Falconry has be active there for more than 2000 years. The Saker Falcon and Peregrine Falcon have traditionally been the birds of choice until Gyrfalcons became available. While the CITIES treaty does not allow for legal import/export of Gyrfalcons, there is a strong captive breeding program within the United Arab Emirates. In fact, the Abu Dhabi environmental agency was a financial sponsor of this conference. They are advancing the genetic analysis of falcon blood lines in the hope to conserve both wild and captive falcon populations. One of the great aspects of this conference is its breadth of topics from history, literature, falconry, conservation, climate science, etc.

Grainger Hunt summarized the challenges facing arctic species, highlighting some of the adaptive responses to the unpredictable conditions. While Gyrfalcons and Ptarmigan appear to be linked, the situation as it often is in nature is far more complex. Each species has its unique adaptations and responses which link them at times and not at others. As rapid change in the arctic unfolds, this system gets even more complex. This is why the top avian scientists working in the arctic were all in the room.

Tom Cade, an individual I have admired through the work of his long career, provided a detailed overview of the biological traits of the Gyrfalcon. Some of the most interesting points: 1) they evolved from the Saker Falcon, but we don't know how long ago (between 15,000 years and 2million years). 2) They can withstand harsh conditions by storing up to 300g of fat and another 300g in their crop! 3) They may even enter a state of torpor (lowered body temperature to conserve energy), which would explain the often lethargic behavior of some birds. 4) 50-90% of annual diet consists of Ptarmigan, but they also eat sea birds, waterfowl, hares, lemmings, and voles. 5) They have a very long reproductive cycles. Females must build nutrient and energy stores for laying long before most prey arrives in the arctic. At the moment they commit to a nest, there is only 3-4 hours of daylight per day.

Kathy Martin followed next with the life history of the three Ptarmigan species in the Nearctic - Willow, Rock, and White-tailed. She presented research evidence into each species different critical population variables. For example, for Willow Ptarmigan juvenile survival and fecundity drive population. For the Rock Ptarmigan its survival of juveniles and older females. For White-tailed Ptarmigan in the Yukon juvenile survival is most important, but for White-tailed in Colorado older female survival is most important.

Eugene Potapov discussed Gyrfalcon diet then Ivan Pokrovsky compared Gyrfalcon distribution in the Palearctic as compared to the Nearctic. In the Palearctic the Peregrine Falcon is the northernmost breeder while in the Nearctic its the Gyr. Gyrs are more likely to nest in trees in the Palearctic as well. Jeff Johnson presented the results of genetic analysis into different plumage colors in Gyrfalcons. They have isolated one specific gene (MC1R) that appears related to the various color morphs and also separates out the Saker Falcon. This has lead to an analysis of distinct populations. Early evidence suggests the Iceland population is unique, the Greenland population is unique, and the rest of the world is one meta-population. More samples are required for more refined analysis. Using this data in a study of nesting dates, the results show that gray males mate later in the season. There must be selection pressure for this. More study is needed.

The discussions from here shifted more toward climate change. Steve Kendall discussed climate change impacts on birds in the Arctic National Wildlife Refuge, the David Douglas highlighted some of the data sources used for climate change analysis. Rhys Green highlighted the utility of bioclimate models and talked through a case study of 450 European breeding birds. The approach he described is a similar approach to what I highlighted in a recent blog post on my thesis study area. Fascinating stuff. The more I see, the more I hope that all of these models are wrong!

In an interesting case study, George Divoky talked about his 40 years of studying the Black Guillemot. The Black Guillemot was never an arctic breeder. They do not fly over land, so were isolated from the arctic until the land bridge disappeared some 21,000 years ago. At this point they still avoided it as their breeding season requires 80 days of summer. With climate change they have been moving north. George documented their first arrival on an island in north Alaska in 1975. Since then the sea ice has continued to retreat, taking the arctic cod with it. As the Black Guillemot shifted their diet to less nutritious fish, brood reduction become more common. The change has also brought in other predators - polar bears due to low ice and Horned Puffins. In the latest breeding season of 183 nestlings - 90 were eaten by polar bears, 83 by puffins, 9 by other forces, leaving only a single fledgling from the colony. During George's career, this island went from too cold, to just right, to too warm. Amazing.

The conference continued, with discussions on Collared Lemming populations which are no longer cycling in Greenland, and then to chemical contaminant levels in arctic species which have been shown to track worldwide usage, even in the fairly isolated arctic. The only good news in this is that the Gyrfalcon has a lower exposure risk than other animals including the Peregrine Falcon. Back to climate change, Travis Boom presented his analysis of climate change's effect on Gyrfalcon distribution based on the climate model processes described above. The result is expected to be a 60% decrease Gryfalcon distribution this century. This is only the climate impact. Ptarmigan are expected decrease and shift their distribution as well. The really bad news - the shifts in fundamental niche are not the same for Gyrfalcon and Ptarmigan thus further decreasing the available niche for Gyrfalcons and putting their survivability in question. All of that research in only the first day of the conference! I had to miss day two as I attended my own classes and taught my labs.

Thursday morning the conference focused more strongly on the Paleartic with Russian scientists presenting their work on the Gyrfalcon and Ptarmigan distribution and dynamics in Siberia. The afternoon was dominated by presentations on the Saker Falcon, the closest relative to the Gyrfalcon, and the Peregrine Falcon which occupies the arctic along with the Gyrfalcon. I have pages of notes on these sessions as well, but will refrain from summarizing it all here.

Every time I listen to research on the arctic, I am amazed at how much faster climate change is occurring up there. As one researcher put it - the world has warmed by 0.6 degrees, but the arctic has warmed by 4-6 degrees. The number of freeze/thaw events per year have doubled. This is having dramatic effects on everything that lives there. Change is happening here too, it is just amplified up there. I have to respect the dedication of the researchers doing this important work. They are working in a very fascinating location, but as most field biologists realize, the glamor quickly wears off when the weather gets bad and the mosquitoes smell your blood. I am sure both can get quite extreme in the arctic. While the arctic may be far away and mostly removed from our daily existence, the chain of events occurring there are connected to everyone's world and will catch up to us at some point. The researchers are working to understand those effects to not only save the species that are threatened today, but also those that will be threatened tomorrow.

I have to thank the Peregrine Fund for putting this conference together. They led the effort to prevent the extinction of the Peregrine Falcon, have fought to save numerous other species around the world, and were instrumental in getting this world-wide discussion started regarding the fate of the Gyrfalcon. There are few organizations with their proven track record and get it done attitude. I am glad I could be a part of this conference.

The Water Birds of Belize

2011-01-23T08:21:00.001-07:00

This is the third post in a series based on Karyn and I's recent trip with two birder/biology friends to Belize. This post is focused on water birds, while the the previous posts included a general overview of the trip - The Pursuit of Wild in Belize - and a post focused on - The Raptors of Belize. I intend a few more posts in the series including one on Mayan ruins and another on the remaining birds not covered in this and the raptor post, so be sure to check back.

Having spent time on Caye Caulker and in the lagoons of Crooked Tree, we did quite well in our observation of water birds. The two top desires from a water bird perspective were to see an Agami Heron, which would be a life bird for all of us, and to see all five Kingfisher species including another group lifer, the Pygmy Kingfisher. I am happy to report that we were successful in each of these endeavors!

The Herons.

We were successful in seeing every heron species in the country, with the exception of the Bitterns. They are a bit more secretive and difficult to track down. The highlight of course was the Agami Heron. We had chosen to go to Crooked Tree specifically for this bird, although as one of the top birding locations in the country we were happy to see many others. On our first night there we were disappointed to hear that it was the wrong season for Agami Herons. The water level was too high. They were expected to be far up in the creeks. Regardless, we booked an early morning boat ride to head as far up Spanish Creek as we could go in a 3-hour tour. We arranged with the guide to omit much of the usual lagoon tour that we had seen with another guide a few days before, and head straight for the creek. Wow, we had an amazing tour seeing four of the five kingfishers and all of the herons, including the Agami!. It may have been a juvenile, but none of us were complaining. Look at the size of that beak! The Boat-billed Heron was another prize. Green Herons were probably the most abundant bird on our Spanish Creek boat trip, tallying over 60 sightings. Wow.

Juvenile Agami Heron. Crooked Tree.

Great Blue Heron. Crooked Tree.

Tri-colored Heron. Caye Caulker.

Little Blue Heron. Crooked Tree.

Green Heron. Caye Caulker.

Boat-billed Heron. Crooked Tree.

Juvenile Yellow-crowned Night-Heron. Caye Caulker.

Black-crowned Night-Heron. Crooked Tree.

Pale-throated Tiger-Heron. Crooked Tree.

The Egrets.

The egrets may not be as exciting as we have all three species here in Idaho. With that said, they are amazing birds and fun to watch. In addition to the Great and Cattle Egrets pictured below, a number of Snowy Egrets also presented themselves.

Great Egret. Crooked Tree.

Where else would you find a Cattle Egret?

The Kingfishers.

Belize has five kingfisher species, one of which is present in Idaho - the Belted Kingfisher. For our first few days on Caye Caulker, Belted Kingfishers were all that we would see. Even the first day at Crooked Tree presented only Belted Kingfishers. We were once again told it was the wrong season for the others. That would change on our boat ride to Spanish Creek. We would see Belted and three other species - Ringed, Green, and Pygmy Kingfishers. Later in the trip we would see numerous Amazon Kingfishers completing the list. The Pygmy Kingfisher was fantastic. It was in low light as the sun had not yet fully risen, but we watched it on its perch then watched as it dove in the water after prey. A nearby Green Kingfisher was visible at the same time for size comparisons.

Pygmy Kingfisher. Crooked Tree.

Green Kingfisher. Crooked Tree.

The largest - The Ringed Kingfisher. Crooked Tree.

Ringed Kingfisher. Crooked Tree.

The Others.

Not to dimish the other water birds, there were some fantastic finds. Numerous Sungrebes presented themselves, which is a rare find. Our early morning start definitely helped.

Sungrebe. Crooked Tree.

The White Ibis as another fantastic find. We had a few on Caye Caulker, but on our first boat ride in Crooked Tree we watched as hundreds flew into the roost for the evening. The picture does not represent the volume of birds. The tree looked full as we watched many additional groups of 50-60 birds each come into the tree. Listening to the racket they were making was amazing. We reported a conservative number of over 360 birds! There could have been double that.

White Ibis and Neotropical Cormorants roosting for the night. Crooked Tree.

White Ibis. Caye Caulker.

Another favorite is the Northern Jacana. They were everywhere at Crooked Tree. I love their long toes which help them walk on floating vegetation. Their wings are a beautiful greenish yellow when they fly.

Northern Jacana. Crooked Tree.

Northern Jacanas in flight. Crooked Tree.

I've always wanted a great photo of a Roseate Spoonbill, but they are always so far away. This is better than I've captured before, but still not what I wanted. They are such funky birds.

Roseate Spoonbills. Crooked Tree.

Clearly Belize is a fantastic place for water birds, specifically Crooked Tree.

Anhinga. Crooked Tree.

Gray-throated Wood-Rail. Crooked Tree.

Willet. Caye Caulker.

Limpkin. Crooked Tree.

Wait, I forgot the Frigatebirds, Pelicans, and the Cormorants... Too many birds, too many pictures...

The Raptors of Belize

2011-01-22T09:32:00.001-07:00

As a Raptor Biologist I feel it is my duty to create a blog post dedicated to the many raptors we observed on our recent trip to Belize. This is a follow up to my first post on the trip - The Pursuit of Wild in Belize.

We tallied 29 raptor species for the trip, but not the most wanted, the Harpy Eagle. They are extremely rare in Belize with only one known nesting pair. We saw all but one of the possible falcons in the area, missing only the Aplomado Falcon.

The Vultures.

We would see all four possible vulture species in Belize. The ubiquitous Black Vulture is seen everywhere, sometimes in groups of 30-40 soaring birds.

Black Vulture.

Often mixed in with the Black Vultures are the second most numerous species, and one that is seen in Idaho, the Turkey Vulture. While Turkey Vultures are also in Idaho, the non-migratory subspecies we observed in Belize is unique from the migratory subspecies found in Idaho.

Turkey Vulture.

Another species often intermixed with the Black and Turkey vultures is the closely related Lesser Yellow-headed Vulture. It is very similar to the Turkey Vulture in flight. Unfortunately I would fail to get a decent photo of its unique face. The biggest of all the vultures is the King Vulture. They are more difficult to observe and photograph as they are often seen flying high overhead. We observed them on at least four occasions including both adults and juveniles.

The Kites.

The most numerous of raptors we observed was the Snail Kite. While we mainly observed them at Crooked Tree, we did report a total of 60 individuals in one evening! They were amazing. They forage for snails over water. You might assume, as I did, that snails would be rather easy prey, but there is a bit more skill involved. The snails climb up out of the water onto the reeds to lay their eggs. If they see a Kite coming, they simply drop off into the water where they are safe. Thus, the kites do have to be stealthy. With that said, we did watch many successful attacks.

Snail eggs on plants - pink = non-hatched, white = hatched.

Juvenile Snail Kite.

Adult Snail Kite.

The other kites were much less numerous with only one or two sightings each - Hook-billed Kite, White-tailed Kite, and Double-toothed Kite.

The Hawks.

The most ubiquitous of the hawks in Belize is the Roadside Hawk, although it is not always seen on the roadside. We probably observed 30 or more of these during our travels. On the Trogon Trail in Crooked Tree we tallied eight birds on a two mile hike. Some of those were juveniles still partially dependent upon their parents. They were vocalizing back and forth regularly.

Adult Roadside Hawk.

Juvenile Roadside Hawk.

Adult Roadside Hawk.

Black is a popular color for hawks in Belize. We saw the Common Black-Hawk, Great Black-Hawk, Black-collared Hawk, Black Hawk-Eagle, and even the Crane Hawk is black. And some "black" hawks we saw remain unidentified. They do each have their unique markings, unique flight style, and unique habitat so it is not quite as hard as it seems. Helping matters is that not all juveniles of these species are black and some, as in the Black-collared Hawk have very distinctive non-black markings.

Juvenile Great Black-Hawk.

Black-collared Hawk.

But there are other colors as well, such as the White Hawk and the Gray Hawk, but we wouldn't see the Bi-colored Hawk.

White Hawk.

Gray Hawk.

The Falcons.

Belize is a falcon paradise. Whether it was a Peregrine Falcon stooping on a Magnificent Frigatebird, an Orange-breasted Falcon stooping on a Turkey Vulture, or an Orange-breasted Falcon delivering a Squirrel Cuckoo to the nest, falcons stole the show. We even saw a few American Kestrels which are supposed to be rare in Belize this time of year. The most pervasive would be the Bat Falcon. Our first pair were apparently nesting on the tower at the airport! We would also see them at a few of the Mayan ruins we visited. I wonder of the Mayan culture had any special acknowledgment of these birds?

Orange-breasted Falcon.

Female Orange-breasted Falcon delivering Squirrel Cuckoo to the nest.

Bat Falcon on airport tower!

Laughing Falcon.

The Owls.

Owls are generally harder to add to trip lists. Their general nocturnal nature make them very difficult to find. The fatigue from our daily routine coupled with the uncertainty of hiking in unknown lands in the dark, limited our pursuit of these species. A few of them did grace our presence. At the Mayan Mountain Lodge we heard both the Vermiculated Screech-Owl and a Mottled Owl. We narrowed the Mottled Owl down to a single tree, but our lights weren't bright enough to find it in the 60 foot high canopy. A diurnal species, the Ferruginous Pygmy-Owl was a bit more accommodating. We found three of these guys during our travels. One was particularly photogenic. I was fascinated by the fake eye-spots on the back of its head. I am definitely painting those on my goshawk tree climbing helmet!

Ferruginous Pygmy-Owl

Ferruginous Pygmy-Owl fake eye-spots.

The complete raptor trip list:

Black Vulture
Turkey Vulture
Lesser Yellow-headed Vulture
King Vulture
Osprey
Hook-billed Kite
White-tailed Kite
Snail Kite
Double-toothed Kite
Black Hawk-Eagle
Black-collared Hawk
Sharp-shinned Hawk
Crane Hawk
White Hawk
Common Black-Hawk
Great Black-Hawk
Roadside Hawk
Gray Hawk
Short-tailed Hawk
White-tailed Hawk
Laughing Falcon
American Kestrel
Merlin
Bat Falcon
Orange-breasted Falcon
Peregrine Falcon
Vermiculated Screech-Owl
Mottled Owl
Ferruginous Pygmy-Owl

The Pursuit of Wild in Belize!

2011-01-20T10:13:00.001-07:00

Karyn and I just returned from an excellent trip in pursuit of wild birds, wild fish, wild animals, and wild culture in Belize. We found most of that and more on our 12 day adventure into the sea and into the jungle. We were traveling with two biologist and birding friends of ours Heidi and Jay, which made for a great wildlife obsessed adventure. We tallied many fish species including two turtle species, nurse sharks and three types of rays, over 250 bird species, 3 Mayan ruins, many new fungi (Heidi is also obsessed with mycetes!), and both annoying and non-annoying insects. The only real disappointment of the trip is the relatively few mammal species we found and no sightings of poison dart frogs. This post is the first of a series of posts covering our trip. This post will provide a general overview. Look forward to future posts on raptors, water birds, jungle birds, and Mayan ruins, so check back soon for an update

Bird nerds! Jay, Rob, Karyn.

The trip to Belize required an overnight stop in Houston. We had hoped to pick up a few bird observations while there, but arriving after midnight and flying out in the morning didn't help. Rock Pigeons from the terminal would be all that we would see. That would change a few hours later as we landed in Belize City. As we rode in the taxi on the way to the docks, the species count started to grow.

The first destination, and our home for three nights, was Caye Caulker a one hour boat ride out from Belize City. Magnificent Frigatebirds, Brown Pelicans, and Laughing Gulls escorted us on our way, while Royale Terns and Sandwich Terns welcomed us to the island.

Caye Caulker waterfront.

First lunch on Caye Caulker - Jay, Heidi, Rob.

We had made reservations beforehand at the Tropics Hotel, a beachside hotel not far from the arrival dock. We chose the Tropics as they also operated the snorkel tours in which we wanted to participate.

Beachside hotel on Caye Caulker.

Little did we know that the hotel butted up against the Oceanside Nightclub. The Oceanside runs Karaoke from 9pm until midnight, then dance music until 4am! After the bar closes, the party moves out in front of the hotel. On the final night the party moved into the hotel. Heroin and prostitutes in the room between Heidi's and ours. Nice! The beds were also the worst I have ever slept on. $20 a night wasn't worth it. Other than no sleep at night, our stay on the island was fabulous. No cars on the island, just walking, bikes, and golf carts. We birded morning and night. The snorkel trip to the Hol Chan marine reserve was great. Swimming with Southern Stingrays, Rough-tailed Stingrays, Spotted Eagle Rays, Nurse Sharks, Green Sea Turtles, Hawksbill Turtles, and tons of fish was outstanding. The coral formations were some of the best I have seen. The Caye Caulker Marine reserve was equally fantastic. We snorkeled there on a custom birding/snorkel trip we put together with some local conservationist's. They didn't have a great boat, but did provided us access to the Caye Caulker Forest Reserve for birds and some excellent snorkel locations.

After three short days it was time to put the sea behind us and head into the jungle.

Returning to the mainland we rented a car and headed to Crooked Tree. This is a hardcore birding destination with not much else to do. There is not a single nightclub in the place! We stayed at Tillet's Village, a huge step up from The Tropics hotel. We were the only ones there and received excellent service. They did try to jack the price up on us, so if you plan to stay there make sure you work that out in advance. The advantage of Crooked Tree is boating the lagoons. Boats provide an excellent way to cover lots of ground and see birds up close, many that you would never see walking on land.

Tillet's Village, Crooked Tree.

Dinner at Tillet's Village. Karyn, Jay, Heidi.

The first night we boated the northern section of the lagoon with the guide from Tillet's Village.

First boat ride at Crooked Tree.

Sunset at Crooked Tree.

The highlight of the first boat ride was seeing 20-30 Snail Kites, Northern Jacanas, Herons, and Egrets. At sunset we watched hundreds of White Ibis fly into their roosting site. Fork-tailed Flycatchers watched us from short grass. On the walk back from the boat we found numerous Common Pauraque jumping for insects.

The next day we hiked local trails finding many land based species, but the highlight was the Vermillion Flycatcher. They were everywhere!

Vermillion Flycatcher. Crooked Tree.

On our final day at Crooked tree, we got up very early for a dawn boat ride to Spanish Fork on the south end of the Crooked Tree lagoons. This was arranged through the Bird's Eye View lodge, a higher end lodge. The guide was excellent and this boat ride was clearly one of the highlights of the trip. We were in search of the Kingfishers and the Agami Heron. We would find four of the five Kingfisher species and one juvenile Agami Heron among many, many other species I will highlight in a later blog post.

Spanish Creek Boat Ride. Crooked Tree.

Our days quickly passed - time to move on to our next destination, the Cockscomb Jaguar Reserve. While seeing Jaguars in the wild is an extremely rare event, we had to give it a shot. We stayed at Nu'uk Chi'el just off the road into the preserve. This was another step up in quality. minutes after our arrival we were amazed by the sight and sound of more than 50 parrots flying overhead. The cottages are managed by one of the five famous Mayan sisters. They are well known for their artwork and we would later find many references to the five sisters. The owners were interesting to listen to as they told their stories. Aurora told us her life history and the story of the five sisters, while her husband told us the challenges of being a leader of the community under a crisis (many teenage suicides in the past few months). We enjoyed their company and their cottages. They use no pesticides so the grounds were covered in flowers, many insects, and of course, tons of birds. Many tanagers, toucans, aracaris, flycatchers, and warblers welcomed us there. Heidi found two different tarantula species!

Dinner hut at Nu'uk Che'il near Cockscomb.

The trails of Cockscomb were our best chance of seeing a Jaguar. Unfortunately we would not. We did find a popular prey species of the Jaguar, a Red Brocket Deer.

Red Brocket Deer. Cockscomb.

We also added Howler Monkeys to the trip list. The birds cooperated by presenting many new species for the trip. We hiked up to a lookout in the sweltering heat, then hiked back down in the rain. We later swam in the river as we watched the fifth Kingfisher species of the trip fly by - the Amazon Kingfisher. Therefore we saw all five possible kingfisher species on the trip! We expected poison dart frogs, but we didn't see any. We did find this forest frog and a few toads.

Frog on Cockscomb trails.

The trip continued to fly by. It was now time to head for our final destination, the San Ignacio area. Here we would diversify our focus from birds to spend more time at Mayan ruins, which just happen to be great places for birds! The accommodations continued to increase in quality. We chose the Mayan Mountain Jungle Lodge. It cost 3-4 times what the Tropics Hotel charged, but was hundreds of times better! Great environment, great food, clean rooms, etc. The owners spent time talking to each table at breakfast and dinner. They even made box lunches for our daily adventures. On the grounds of the lodge we also found some very rare species for the area including a Black-throated Blue Warbler. A Blue-crowned Motmot greeted us daily as well as nearly a dozen Ladder-backed Wrens.

Maya Mountain Lodge near San Ignacio.

Blue-crowned Motmot.

Next up was a trip to the Caracol Mayan ruin. This involves a 50 miles drive on a rough gravel road. The road is tough on vehicles and has a reputation for attracting Guatemalan bandits as it is near the border. Therefore a military escort is "highly recommended". We chose to forgo the military protection and head in an hour and a half early. Therefore we had the place to ourselves until the convoy arrived.

Tropical rainforest on drive to Caracol.

Road to Caracol.

The temples were fantastic. I'll focus a later blog post on the area. This city was one of the power centers of the Mayan empire and thrived for 1500 years. It was fascinating to imagine the city at the height of its prosperity.

Caana temple. Caracol. Jay, Heidi, Karyn climbing down.

Strangler Fig.

Jungle.

Montezuma Oropendola nest near Caracol. Heidi, Jay, Rob.

We wanted to stay longer, but the military escort on the return trip was less optional. The man with the gun explained how important it was that we leave. He made very valid points. If something did happen, it would impact the whole local tourist economy for years to come. We reluctantly agreed and departed on our way. It was interesting that the very next day at a ruin that straddles the border with Guatemala, there would be no escort, and no guards at all. We were free to walk to Guatemala if we wanted to.

Next up was El Pilar, a Mayan ruin which remains largely unexcavated. The book says it requires a bit more imagination. It was great to see the contrast from the fully excavated Caracol. It too was very enjoyable to explore and we could stay as long as we wanted. We found tons of birds along the road to the ruin and at the ruin.

Unique approach to birding ON the road to El Pilar. Jay, Heidi, Rob.

Karyn preferred the car.

That afternoon we hit one more ruin just outside of San Ignacio - Cahal Pech - "Land of the ticks!".

The final day arrived. How could it go so fast... The schedule for the day was to once again brave the rough road toward Caracol, but turn off toward 1000-foot falls. Orange-breasted Falcons were rumored to nest here. We would not be disappointed in our pursuit as two falcons demonstrated their aerial skills by first stooping on a Turkey Vulture, then later delivering food to the nest - a Squirrel Cuckoo!

Orange-breasted Falcon with Squirrel Cuckoo at 1000-ft Falls.

From the falls we headed back toward Belize City spending the night in Belmopan. A quick 45 minutes in Guanacaste park in the morning, then a dash to the airport for the long, but uneventful flight home.

Climate change and Aspen in south-central Idaho

2011-01-02T13:18:00.001-07:00

As an certifiable bird nerd and aspiring raptor biologist, I have always known that climate change poses a huge threat to birds, raptors, and essentially most life on the planet. However, I am probably similar to most people in the world by not knowing exactly how this impact will take place. Well, that is changing...

Climate change is not a popular topic today. It seems that most people are more focused on the economy and their jobs and not on the the looming threat of climate change. The onion, one of my favorite satire sites, posted an excellent story a few weeks back: Report: Global Warming Issue From 2 Or 3 Years Ago May Still Be Problem.

As I prepare my master thesis proposal on the breeding ecology of Northern Goshawks, I am uncovering shocking predictions, shocking in both scope and in its timeframe. While I am not pursuing a study of climate change per se, I am studying the impact of climate change upon the ecosystem and specifically upon Northern Goshawk productivity. Work out of the Moscow (Idaho) Forestry Science Laboratory of the Rocky Mountain Research Station of the USDA Forest Service has classified key variables influencing different forest structures. In Rehfeldt et al. (2006) the team developed the generalized models across the western United States. In Rehfeldt et al (2009) the team explored the specific relationship of climate change on Aspen Viability. I am particularly interested in Aspen as all known Northern Goshawk nests in my study area are located in Aspen. The U.S. Forest Service (2003) documented that Aspen within my study area was either "at risk" or "not functioning correctly". I know that some goshawk nest trees have fallen down in the last few years. Thus, I have chosen part of my research effort on understanding what risk Aspen decline has upon the Northern Goshawk in this area.

Rehfeldt et al. (2009) studied which climate predictors were most significant in predicting the presence of Aspen across the west. They found that the annual dryness index, the ratio of summer to annual precipitation, and the interaction of growing season precipitation with the summer-winter temperature differential to be the most significant variables influencing the presence of Aspen. Below is an image of the Aspen viability scores overlaid on my study area, specifically the South Hills and the Albion Mountains. This fairly accurately represents the current range of Aspen in the area. If anything it is very generous in its prediction.

Aspen viability today within the Minidoka Ranger District of the
Sawtooth National Forest based on Rehfeldt et al. (2009).

After showing the predictive power of the climate variables, Rehfeldt et al. (2009) then applied changes predicted by various climate models and scenarios to predict the future viability of Aspen. They chose to use the climate models championed by the US, the UK, and Canada. Upon each of these climate models, they used two different scenarios producing six different predictions. While each of the six predictions are slightly different, they are consistent in one area - Aspen is in trouble in the Minidoka Ranger District! The image below represents the climate model 2.1 from the U. S. Geophysical Fluid Dynamics Laboratory (part of NOAA) combined with the Aspen variables to illustrate the viability of Aspen in the decade surrounding 2030 (a mere 19 years away!).

Aspen viability in 2030 within the Minidoka Ranger District of the
Sawtooth National Forest based on GFDL climate model 2.1 (Rehfeldt et al. 2009).

The 2060 and 2090 predictions aren't worth showing - nothing but red. If these predictions are correct, this will be a tragedy of unfathomable dimensions. Aspen forests are one of the most productive temperate ecosystems. Hundreds of species are dependent upon these forests. Focusing only on raptors, these Aspen forests in the Minidoka Ranger District house Northern Goshawks, Coopers Hawks, Sharp-shinned Hawks, Northern Pygmy Owls, Flammulated Owls, Northern Saw-whet Owls, Great Horned Owls, and probably others. Those are the species that I personally have seen and heard there! Woodpeckers include the Northern Flicker, Hairy Woodpecker, Downy Woodpecker, and Red-knaped Sapsucker. I could go on... Even the State Bird, the Mountain Bluebird lives in Aspen forests. Its a sad, sad story.

I don't know what my call to action is other than to do whatever you can to decrease your carbon dioxide generation.

Sources:

Rehfeldt, G. E., N. L. Crookston, M. V. Warwell, and J. S. Evans. 2006. Empirical Analyses of Plant-Climate Relationships for the Western United States. International Journal of Plant Science 167: 1123-1150.

Rehfeldt, G. E., D. E. Ferguson, and N. L. Crookston. 2009. Aspen, climate, and sudden decline in western USA. Forest Ecology and Management 258: 2353-2364.

U.S. Forest Service. 2003. Sawtooth National Forest revised land and resource management plan. Sawtooth National Forest. Twin Falls, Idaho USA.

How can you not love waxwings?

2010-12-21T15:02:00.001-07:00

In preparation for our upcoming birding trip to Belize, I thought I should take in some sunny weather to practice using our new camera. Remembering the Cedar Waxwings from the Christmas Bird Count, I headed to Dry Creek Cemetery. I found the waxwings and a few other birds, but the Varied Thrush remained elusive. Waxwings are definitely one of my favorite birds.

Cedar Waxwing.

Two Red-tailed Hawks flew overhead, one chasing the other. The chasing bird retreated to the top of the highest tree and proceeded to exclaim that this was his territory. Mating season may still be months away, but a productive territory is always worth defending.

Adult Red-tailed Hawk.

Counting the birds for Christmas

2010-12-20T08:28:00.001-07:00

Yesterday I participated in the Audubon's 111th Christmas Bird Count. It was the 44th Christmas Bird Count held in Boise.

The Christmas Bird Count is an important long term study of bird populations across the country. Since it has amassed such a large data set, it has been a critical resource for assessing bird populations and distributions over time. This makes it the most significant citizen science project currently underway.

In communities across the country, volunteers spend an entire day counting every bird they can find. The count is restricted to a 7.5 mile radius from a chosen central point. The Boise count is centered in the Idaho State Capital. About 30 people showed up at 7am on a Sunday morning under snowy skies and nasty roads. The "count circle" was divided by the organizers into a number of sections. I paired up with two other volunteers I didn't know and headed out into the snow surveying a section of NW Boise. It's a great way to meet new people.

The skies lightened up a little bit around sunrise providing a great start to the counting. Hundreds of Canada Geese, American Wigeons, and of course the ever present invasive European Starlings. The species racked up quickly. About an hour into the count, Sue's car died. Dead battery. We flagged down some help to get a jump start, but we definitely needed to move on to plan B. We retreated to Gary's house so he could borrow his son's car. Unfortunately Sue had to leave us for the day.

Gary and I headed to Dry Creek Cemetery. Lots of bird action here - Cedar Waxwings, Red-Breasted Nuthatchs, Cooper's Hawk, Sharp-shinned Hawk, and then I found a Varied Thrush. The Varied Thrush is a great bird to find! Dang, my camera was back in the car. I went to get it, but the thrush was gone when I returned. The lighting wasn't too great for photos anyway.

Cedar Waxwing.

Adult Cooper's Hawk (maybe second year).

Next up was Hidden Springs. Only about half of Hidden Springs is within the count circle. We had to check it out as some rare birds had been seen there is previous weeks. No rare birds, but we did get some good species such as Western Screech Owl and Great Horned Owl. The snow started again, somewhat mixed with rain. Along Pierce Park we found a life bird for me, a Northern Shrike. In fact we found two! This was a great find for the count.

Northern Shrike.

In a particular group of trees, I thought I had heard a Northern Pygmy Owl. We searched and searched, even played their call on an ipod. No response. Then I saw a Townsend's Solitaire. Gary played the solitaire's call and that was it. It's very close to the quality of an owl. I realized I had never heard their call. The pygmy owl would have been a great bird, but so is the solitaire.

Moving back into the Boise neighborhoods, the rain slowly picked up and visibility dropped. We continued counting, but the new species declined. I had to leave at 3:30, so Gary continued on his own. When I left him we had counted 40 species for the day and thousands of individual birds. I won't have the totals of the whole Boise count circle for a few more days, but I expect the number of species to be near normal, which is usually around 80 species.

Rare Visitors and Snow Days

2010-12-01T15:44:00.001-07:00

The talk of the birding community within Boise for the past week has been the presence of two very rare warblers in Idaho. I first received the call on Thanksgiving Day just before dinner with my in-laws. This was not the best time to go running in pursuit of a few lifer birds. Or maybe it was, but I chosen to maintain family relations instead. The following day we left for a weekend in Sun Valley. I had mostly forgotten about the birds until receiving word yesterday that they were still around. I decided that Wednesday afternoon would be my chance.
Wednesday morning we awoke to about 7 inches of new snow and still more falling from the sky! This is an unusual amount for Boise. Shortly before heading to school I received a text message from the University indicating that classes were canceled. It was time to go birding! Since all the wimpy drivers stayed home, we had no problem making it down to the river.
Would the birds still be around with this much snow? Would they be hiding? Karyn and I's first walk through the snowy area failed to find anything but House Sparrows. Walking down river there were plenty of Canada Geese and Mallards. We could hear Belted Kingfishers in the distance and then the call of a Bald Eagle.

Juvenile Bald Eagle, probably 3rd year.

Walking back to "the spot", we noticed some small birds moving through the trees. I pull up my binoculars and there it was, my first ever view of a Yellow-throated Warbler! This bird is only the 3rd report ever in Idaho. I moved in for a photo, but none was to be had. I lost him. I continued searching until I found the other rarity, a Northern Parula! Lifer #2! This is only the 12th report ever in Idaho of a Northern Parula. I had to get a photo.
The bird would not hold still. It was moving through the branches foraging. I was juggling binoculars and the camera to try for a shot. The viewfinder was covered in snow. I couldn't tell if the camera was focusing or not. At one point the Parula was chased by a Ruby-crowned Kinglet. There he was still on a branch! Snap.

Northern Parula!

Dang, missed him! Another attempt.

Northern Parula.

Warblers are sooo hard to get wild photos of. Finally.

Northern Parula.

We searched some more for the Yellow-throated Warbler, but we never located it again.

Playing in the Snow

2010-11-28T20:06:00.001-07:00

Winter has arrived in Idaho. It came quickly with very cold weather and plenty of snow. Karyn and I had planned to hit Sun Valley last weekend, but it didn't work out. We did make it on Friday for three great days of cross country skate skiing. I can definitely feel it throughout my body as I sip my brandy on this Sunday evening. But it wasn't all about skiing. We headed out Saturday afternoon in search of wildlife. While we missed some of the spectacular rare birds which showed up in Boise (Northern Parula and Yellow-throated Warbler), we did get a good look at a number of my favorite winter birds.
I saw my first Rough-legged Hawk of the season. Apparently it is a good year for Rough-legged. They are regular winter residents of Idaho, but some years their numbers are very high. I only saw one but other reports total into the hundreds for a single day! Next on my list of favorites are the Snow Buntings.

Snow Bunting near Ketchum Idaho.

They are usually found in flocks, but this guy was solo. Another year round favorite of mine is the American Dipper. I love watching them diving in the water, but it is even more spectacular in the winter with the snow and ice. We saw more than a dozen on Warm Springs Creek.

American Dipper near Ketchum Idaho.

Even though I am a bird nerd, we do like other wildlife as well. We would see hundreds of Elk, a few dozen Mule Deer, a couple of Coyotes, and Karyn snapped this photo of a friendly Beaver which entertained us for 30 minutes.

North American Beaver, Warm Springs Creek.

Great skiing, great wildlife, and great food made for a great weekend together. Now its back to school for a few more weeks.