Anniversary Date

On July 14th, fifteen years ago, Karyn and I were married on a mountain bike trail in central Idaho. Each year we return to the area to play until we can't take any more. This is that week.

Our anniversary day began with breakfast at the Stanley Baking Company. Yes, roughing it in the wilds! Blackberry scones, oatmeal pancakes, a side of sausage, and great coffee. Mmmm! This being our fifth day of riding, we have to fuel up! From there we headed out to the Fisher Creek mountain bike trail. I featured this trail in a previous post. We had to let our breakfast settle, so we spent some time bird and flower watching at the trailhead.

Sawtooth Mountains.

Karyn took this great photo of me at the trailhead. Don't I look like a fertility statue?

Fertility Geek.

On to the ride. The trail climbs gently for a number of miles before hitting a very steep climb. We cleared the hill without dabbing. At the top of the climb we stopped to recover. I thought I had glimpsed a Black-backed Woodpecker here the last time we rode it. I decided to pick up a rock and tap out my best Black-backed drumming impression.

Black-backed Woodpecker Impression.

No luck on a Black-backed Woodpecker, but I did raise the ire of a Hairy Woodpecker. He scolded me from the hill above and then flew closer to defend his honor and his territory. Closer and closer he moved. I had not repeated the drumming, be he seemed to know the exact tree the sound had come from. He moved to within 15 feet, looking for the intruder. We left him in peace, still puzzled about our identity.

After the first tight and twisty downhill section we arrived at the meadow where we were married. Karyn and I stopped to look for frogs and salamanders. No, that's not slang, we really were looking for frogs and salamanders. Get your mind out of the gutter! None here. We have had a hard time finding frogs this year. Not sure why.

In the meadow where we were married.

I tried my woodpecker magic again at the meadow. A lone Northern Flicker responded from across the meadow, but did not come to investigate. At the top of the next hill, I tried again. A Flicker responded with calls from one direction and an unidentified woodpecker drummed from another. This really is a leisurely day. Last week we hammered out this trail in 1:45. This week it took 3 hours!

The big downhill was great fun, although a recent storm had blown down a number of trees. We managed to stop before hitting any of them. It was a fun and interesting ride as we explored along the way. It could have been called the tour of the woodpeckers. In addition to the Hairy Woodpecker and Northern Flicker, we also saw both Williamson's and Red-naped Sapsuckers.

The afternoon was spent enjoying more wildlife as we continued our search for birds, frogs, and salamanders. We have found a few frogs, but we really want to find a Blotched Tiger Salamander. We read about them a few months ago while in Yellowstone. Karyn remembers seeing one a few years ago. Have been searching since to try and find one. No luck so far.

We concluded the day with dinner at the Redfish Lake Lodge overlooking the Sawtooth Mountains.

Nesting season at higher elevations

This is Karyn and I's anniversary week. We are spending it in the mountains where we were married fifteen years ago this month. Mountain biking, hiking, bird watching, and generally relaxing.

Not surprisingly, we have noticed that bird nesting season at this elevation (6500-7500 feet above sea level) is a little bit behind what we see in the city (2900 feet above sea level). The Owls, Hawks, and Robins have mostly fledged in town. Some Goose goslings even look full grown. Up here it looks as if we have stepped back in time a couple of months. At this elevation, most birds are still in their prime nesting activity.

From our campsite next to the Salmon River we can watch two separate nests. High on the hill above the camp, in an old snag, is a Red-tailed Hawk nest. Down river is an active Osprey nest! The Red-tails have two chicks which are nearly full size. This couple is unique. The assumed to be male is a dark morph Red-tail. The assumed to be female is fairly dark, but her chest and abdomen are colored red, almost to match her tail. She is a beautiful bird. I keep hoping for a closer encounter so I can get a photo. The Ospreys are also raising two chicks. We can watch them eating sushi regularly.

On a tandem ride on the Knapp Creek-Valley Creek loop, Karyn found a woodpecker nest. We could hear the chicks inside the tree chirping. I walked up to the tree to listen. The tree was in the sunshine so I reached up to shade the nest hole with my hand. The chicks went crazy soliciting for food! Not wanting to disturb them further, we retreated a distance away to watch. The female returned to the nest. It was an American Three-toed Woodpecker! Very cool! This is a life bird for me! We are located right on the edge of their usual range. The female brought food to the chicks, then extracted a poop sack and flew away with it. Very cool. Early nestlings excrete into a membranous sack so that it can be easily taken away to keep the nest clean. Built in diapers! I am sure we could find many other nests if we spent time looking.

The Great Owls. We pulled a Great Owl double! It started by revisiting the Great Gray Owl family that we located a few weeks ago. Once again, we could only find a single adult, but that was pretty amazing in itself. That evening we were seranaded to sleep by a pair of Great Horned Owls. That's pretty cool.

Day of the mammal. Not to give all of the attention to the birds, we have seen a number of cool mammals as well! Our camp was visited by a small Mink and a cute little Kangaroo Rat, along with the ever present Columbian Ground Squirrels. We are supposed to be outside of the range for the Kangaroo Rat, but he seemed to be making himself at home. Uinta Ground Squirrels and Golden Mantled Ground Squirrels have been present with along with chipmunks on our bike rides. We found a family of Muskrats in a favorite marsh where we look for birds. At least 4 little fuzzy babies swimming about while the adults are busy working! Pikas! Always a favorite. We have seen Elk on a few occasions. We found a herd and also spooked up bull while out on a ride. So much for the rumor that the wolves killed them all. We did find fresh wolf tracks in the mud, but have yet to see a live one on this trip. Deer have been out and about as well. The bucks have antlers, but they are still in velvet. We have searched a few times for a Badger with no luck. It hasn't all gone to the birds!

The greatest mountain bike trail on earth

Fifteen years ago this month, Karyn and I were married. The wedding was a bit out of the ordinary as we were married on our tandem mountain bike. Our witnesses, Doug and Peggy, were escorting us on their tandem mountain bike. My brother and Karyn's sister rode single mountain bikes so they could take pictures. The minister hiked in to perform the ceremony. The location was in the middle of our favorite mountain bike trail, Fisher Creek in central Idaho. The custom bike jerseys were sewn by my mom.

Fisher Creek Trailhead 1994.

This last weekend Karyn and I were in the Stanley area as I performed my Nightjar survey. We had an opportunity to ride the trail on our much newer Ventana full suspension mountain tandem (anniversary present two years ago!). I took along the handlebar camera to let you see what it is like. Remember, Karyn cannot actually see the trail in front. Its all about trust. After 15 years, she still rides with me, so I must have earned some along the way, or at least not lost too much!

The trail has a big climb and then three downhill sections separated by shorter climbs. This is a rare trail in that it seems like more downhill than up. This first section is pretty tight, thus the speed is fairly slow. On some of the switchback corners we must come to almost a complete stop before leaning to get the bike around. The end of this first video shows us arriving in the meadow where the actual wedding ceremony was held.

Wow. That was fun. There is a medium climb before the next section. This next section is the longest downhill on the trail. I had to trim the video a bit on the front and end to keep it under 10 minutes (Youtube limit). You will note that we come up behind a motorcycle who pulls off to let us by. It looks like we scared him off the trail! This is also a very fast section of trail.

After another short climb, it is all speed, except for the downed tree, to the end of the trail. It is a great 17 mile trail and my overall favorite on the planet! Well, I could be a bit biased on that one for sentimental reasons. Anyway, it is a great trail rivaling any in the popular mountain bike destinations.

We will be riding the trail again next week as we return to actually celebrate our anniversary.

idaho, mountain biking

Another Null Survey

Last year I made a multiple year commitment to survey for NightJars one night a year. NightJars are a family of crepuscular/nocturnal birds which in our area consist of the Common Nighthawk (not really a hawk!) and the Common Poorwill. Neither are really that common! Last year resulted in a good time, but a Null Survey. This year unfortunately produced similar results. It was however a great weekend regardless.

The survey is part of a nationwide effort led by the US NightJar Survey Network, part of the center for Conservation Biology of the College of William and Mary. They have mapped routes across the country and have asked volunteers to sign up for surveying a route, preferably for multiple years. It is believed that Nightjars are in a dramatic decline. This multiple year survey is intended to provide a basis for determining their population.

The surveys have to occur within a certain time frame (2 weeks in Idaho), on a clear night, with the moon visible. I chose early in the two week schedule as the moon rises later each day. Early in the cycle the survey can begin at 10pm. Late in the cycle it cannot begin until 2am!

We recently heard reports of a Great Gray Owl family in the area. Karyn and I headed up soon after my classes were out for the week to get a good campsite and to search for the Great Gray Owl. We did not find the family, but we did find one of the adults!

Great Gray Owl adult.

This adult was calling by vocalizing a single low call note. The call was answered by another Great Gray which was further back in the trees, probably 100-200 feet. We didn't see the others, as we didn't want to stick around too long and potentially disturb a new family. It is somewhat rare for them to be nesting in the area. I hope they are successful in raising their young and return to nest in future years.

While the day was beautiful the clouds poured in that evening. We would have to delay the nightjar survey for at least a day. We did go out wildlife watching where this Bald Eagle made its appearance.

Bald Eagle (Karyn's photo).

Friday morning we hiked down the Marsh Creek trail. Lots of birds - Western Tanagers, Ruby-crowned Kinglets, Yellow-rumped Warblers, Yellow Warblers, Hairy Woodpecker, Mountain Chickadees, Chipping Sparrows, Warbling Vireos, Swainson's Thrushes, etc. We saw one hummingbird which might have been a Rufous, but as they often do, it wouldn't hold still. For the non-avian fans, there were lots of Pikas, relatives to rabbits. We passed 5 scree fields, each supporting at least one or two.

Pika collecting grass.

That afternoon, the clouds rolled in. We might have to cancel our survey again! If not tonight, then next weekend at 2am! nasty! We ran into some friends who were also camping. They invited us to dinner. Excellent dutch oven prime rib. About 9pm, the sky began to clear. Woo hoo! We decided to go start preparing to conduct the survey. At 9:30pm it looked better still, we were on! We drove to start the survey.

We started the survey at 10:02pm. The survey consists of a 6 minute listening period performed at each of ten sites, each separated by one mile. Since we had surveyed this route last year, all of the points were established and loaded into my GPS unit. Thus, the whole survey would take just under 2 hours. In each six minute period, we note how many of each species of Nightjar that is heard. Simple enough. Except, there were no Nightjars to be heard. Bummer. However, it was a beautiful night with no wind and a nearly full moon. Numerous Wilson's Snipes were winnowing in the distance. This is a sound that their tail feathers make as they perform aerial flight displays. Six or seven of the points had snipes that could be heard in the distance. We heard one coyote howl.

The null survey is still a very valuable result, equal at least in value to a survey where birds are found. A single survey with no birds doesn't mean that there aren't any there. Two surveys with no birds still doesn't prove their absence, but it does decrease the chance. This particular area is prime habitat for NightJars. Why aren't they there?

Today before we headed home we had a great Mountain Tandem ride on the Fisher Creek Trail. The trail we were married on 15 years ago, on a mountain tandem! Videos from that will be posted later.

On the way out of Stanley we spied a Sandhill Crane chick!

Sandhill Crane family (Karyn's photo).

This is the first chick we have seen this year. It was running back and forth between the parents whenever they would grab some food. In all, it was a great weekend.

idaho, birds, birdwatching, wildlife, biology

First day of banding Songbirds

This morning I arose very early to ride my motorcycle up to the top of Lucky Peak to the Idaho Bird Observatory to help, but mostly learn how to band songbirds. Later in the summer I will be spending a great deal of time up there working with the bird banding team. My research is focused on migratory timing between avian predators and avian prey, using data from the Idaho Bird Observatory. As a result I will participate in song bird banding, hawk watch, hawk banding, and owl banding. The songbird migration banding will be performed daily starting July 15th. Today's banding is part of a reproductive territory banding program coordinated with many banding stations across the country. The team bands one day out of every ten for this program. I volunteered today to help, but also to start my training program for later in the summer.

It was a fantastic experience. The crew of volunteers were very generous in their instruction. I feel overwhelmed by all of the knowledge they attempted to plant in my brain. If half of it sticks I will be doing well! I have visited the Idaho Bird Observatory a number of times in the past, but did not fully appreciate all of the details that are decided upon behind the scenes. Detail like how old a feather was on a given species. The ease of determining this is different from species to species and sometimes requires species specific molt pattern knowledge. It's a good thing they had books nearby. Even the most experienced were looking up species specific details.

My hands on experience today included how to properly hold birds, transferring birds, taking all of the vital measurements (primary length, weight, age of each feather group, age of bird, etc). I only accidently released one bird. Good thing they had already recorded the necessary information! To my knowledge I didn't injure any! I claim that as success. I will need significantly more practice before I am able to fully process my own bird, but I made great progress today.

There were a couple of interesting observations today. We captured a few juvenile (born this year) Song Sparrows. These are not know to nest in the area, so these individuals likely dispersed from this hatch site. One had a "fault bar" on its tail. This indicates that the bird was under nourished during the critical phase of tail feather development. The good news is that he/she appears to be doing well now. I had no idea that this was visible on feathers, but it makes sense.

Juvenile American Robin

We processed this juvenile American Robin then quickly returned it to its mother. She was not happy.

MacGillivray's Warbler.

The MacGillivray's Warbler is distinguished by its bold partial eye-ring. If you look closely in the picture you can see that some of the feathers on the head have a bluish tint (adult) and some look dirtier and brownish (juvenile). This indicates that this bird is a second year bird which is still molting its adult plumage.

Ruby-crowned Kinglet.

I love Ruby-crowns. Who wouldn't!

Visitors.

Part of the day was spent educating others. This group came up for a couple of hours and learned a lot about birds. They were great kids. Jay and Heidi put a male and female MacGillivray's in front of them and asked if they were the same species or not. The group was split, but a number had it right. They all had good reasons for their answer. It was a great experience for them and it was great to see these kids out learning about nature.

Orange-crowned Warbler

The Orange-crowned Warbler was one of my favorites. The photo doesn't do his orange crown justice. He was clean and beautiful!

I'm excited for my continued work at the IBO. I will be back up there on July 18th. I can't wait.

Other birds banded not mentioned above: Chipping Sparrow, Warbling Vireo, Hammond's Flycatcher, Spotted Towhee, Western Tanager, Ducky Flycatcher, Lazuli Bunting, Yellow-rumped Warbler (Audubon's sub-species), Yellow Warbler. Netted, but not banded: Calliope Hummingbird.

birds, banding, biology, research

Diversions

On a lighter note, I discovered a new online beta tool which looked fun. This tool, called TweetPsych, analyzes your twitter comment stream (same as my Facebook comment stream) and provides some observations about your writing style and what you tend to write about. I found this particularly interesting and appropriate.

The scores provided indicate the topic or styles that are used more than the average twitter user. I am not sure I could describe the average twitter user, but oh well. Anyway, the most interesting thing in the results to me is that my score for "Time" is off the charts. Those who know me will likely agree with this result. In fact, I am so obsessed with time that my wife and friends call me the Chrono-nazi! I had to laugh when I saw this. In the primordial content area "Temporal references" rated highest. Wow, these guys have me nailed! "Education" ranking high should not be a surprise with my current schooling. "Numbers" also not a surprise, my first degree (1988) was in Mathematics and Computer Science. I am not sure how useful this is, but it was fun.

From the analysis of my Twitter comments

The features displayed below are those for which you score higher than the average. The score indicates how much more often you tweeted something that matched each feature than the baseline.

Cognitive Content

Feature	Description	Score
Time		209.99
Education	You often talk about school and learning.	141.57
Number		99.31
Occupation & work	You talk a lot about jobs and your work.	84.26
Upward motion	You often make references to physically upward movement. Like upstairs, climb, etc.	55.23
Past tense	You tend to talk about the past.	43.47
Space		19.03
Metaphors	Many of your tweets contain metaphors.	10.3
Sensations	You tweet about your various senses often.	7.81
Motion		7.47
Physical references	You often talk about the physical characteristics of things.	7.19
Leisure		6.08
Certainty		5.73

Primordial, Conceptual and Emotional Content

Feature	Score
Temporal References	111.32
Glory	91.62
Constructive behaviors	45.09
Order	35.21
Narcissism	34.42
Visual sensations	24.48
Concreteness	23.07
Cold sensations	16.89
Aggression	16.82
Sadness	7.64

Calm after the storm

Last night we had some strong thunderstorms moving through the area. That put a bit of a damper on the bar-b-que we were attending at a friends house. It was moved inside and the food was excellent.

Doug had mentioned that last week a group of owls invaded his back yard. As far as we could tell from his description, they were Northern Saw-whet Owls (Aegolius acadicus). Last night at a little past 9pm, we could hear them outside. We went into the backyard and found we were surrounded by owls! Two in this tree, one on the fence, one on the power line, and another in the next tree. They were all chattering to each other and fairly oblivious to our presence. They appeared to be recent fledglings that were begging for food. It was a very cool experience.

This morning Karyn and I went on our local hike through the foothills looking for birds. It was a great day. We saw a lt of the usual species - American Robins, Yellow Warblers, Black-headed Grosbeaks, Bank Swallows, American Kestrels, Red-tailed Hawks, California Quail, Northern Flickers, etc. The Bullock's Orioles were out and very visible with their bright colors.

Bullock's Oriole.

We checked out the Cooper's Hawk nest. The chicks were not visible. The female kept a watchful eye, with the male in a tree nearby. They have at least two chicks in the nest, but we wouldn't see them today. We did get a great view of the Yellow-breasted Chat for the first time this year. They are usually i this area every year. The Great Horned Owls (Bubo virginianus) have been absent as of late, but they were back today. We could only find two of the three chicks which had fledged, and one of the adults. We hope the other fledgling is alive and safe.

Great Horned Owl Fledgling.

Continuing the hike we found a Downy Woodpecker, an American Robin on a nest, and another Robin nest full of 4 large chicks. In the lower pond the Pied-billed Grebe was out feeding a chick. Only one. I wonder if that is all she has.

Pied-billed Grebe.

Research Proposal - Correlated fall migratory timing between avian predators and avian prey

Some of my readers have asked what my research will be focused on. Here is the work in progress proposal that should provide some good background.

---

Research Proposal

Robert Miller

Boise State University
June 2009
Research Adviser: Jay Carlisle; Academic Adviser: Jim Belthoff
Revision: 0.2

This document provides a foundation for a proposed undergraduate research project in the area of Biology/Ecology.

Purpose of Research

This research project was chosen to meet a number of personal and educational objectives including:

• Build knowledge and experience in conducting self directed research.
  
• Build experience and demonstrate proficiency in biological research.
• Contribute meaningfully to the base of scientific knowledge.
• Achieve educational credit for research (2-3 credits in Fall 2009).
• Pursue publication and presentation of research results.
  

Research Topic

Correlated fall migratory timing between avian predators (specifically accipiter hawks) and avian prey (specifically songbirds).

Hypotheses

Avian predators pace their fall migratory speed based on the speed of their primary food source, songbirds. This causes a strong correlation between peak songbird numbers and peak accipiter numbers, that cannot be explained by other phenomenon.

Methods

The data for the study has or will all be collected at the Idaho Bird Observatory. Historical data from the past 12 years combined with new data for 2009 will be included in the analysis.

The focal species of this study will be Sharp-shinned Hawks (Accipiter striatus) and Cooper's Hawks (Accipiter cooperii) as the avian predators of interest, along with total numbers of songbirds (unless I later find specific species relevancy).

The predator data source will be the hawk watch counts, not capture data. Songbird data will consist of capture data.

Attempts will be made to show a stronger correlation between accipiters and songbirds than with any other possible contributing factors - non-accipiter timing, weather (cold front passage, temperature, wind speed/direction), Julian date, etc.

Multiple statistical methods are required and are still under investigation.

Implications of Research

A great deal of research has been performed on the migratory processes and ecology of avian species, yet significant gaps in our knowledge still exist. Migration is a very significant event in the annual cycle of avian species increasing their metabolic requirements to 10-25 times the basal rate (Gill 2007).

Migratory birds make great biological indicators. Migrating Raptors meet or exceed 13 of the 14 "ideal" indicators of environmental health (Bildstein 2001). Through human development (loss of habitat, pollution, and anthropogenic climate change), migrating birds face greater challenges than ever before. According to Birdlife International (2009), "there has been a steady and continuing deterioration in the threat status (relative projected extinction risk) of the world’s birds since 1988." Increasing our overall understanding of the ecology of avian species can help in the conservation and management of these species to decrease the threat against them.

This research builds on the fundamental research of others. Aborn (1994) has illustrated the correlation of accipiter and songbird numbers passing through Southern Mississippi. Cimprich, et al (2005), has analyzed predator prey behavioral relationships between songbirds and accipiters. Allen, et al, (1996), have shown the correlation of accipiter volumes related to regional cold fronts at Hawk Mountain Pennsylvania, while Titus & Mosher (1982) analyzed the impact of wind direction, speed, and visibility on raptor volumes. Bringing this work together with a focus on the predator prey timing relationships is novel.

Expected Timeline

	May	June	July	Aug	Sept	Oct	Nov	Dec
Background Research
IBO data collection
Core analysis
Documentation
First Draft Paper

Resources Required

The following resources are required to be successful.

• Personal time - Committed.
• Access to the IBO data - Committed.
• Peer consultation and review - Committed.
• Regular advising and consultation (1 hour every 2 weeks) - Not committed.
  
• Statistical consulting and review - Not committed.

Initial Literature Review

Aborn, DA. 1994. Correlation between raptor and songbird numbers at a migratory stopover site. The Wilson Bulletin 106:150-154.

Allen, PE., Goodrich, LJ., Bildstein, KL. 1996. Within- and Among-Year Effects of Cold Fronts on Migrating Raptors at Hawk Mountain, Pennsylvania, 1934-1991. The Auk 113:329-338.

Bednarz, JC., Klem, D Jr., Goodrich, LJ., Senner, SE. 1990. Migration Counts of Raptors at Hawk Mountain Pennsylvannia, as Indiciators of Population Trends, 1934-1986. The Auk 107:96-109.

Bildstein, KL. 2001. Why Migratory Bids of Prey Make Great Biological Indicators. Pages 169-179 in Bildstein and Klem, Eds. Hawkwatching in the Americas.

BirdLife International, Global Species Programme. IUCN Red List (updated 2009). http://www.birdlife.org/action/science/species/global_species_programme/red_list.html

Cimprich, DA., Woodrey, MS., Moore, FR. 2005. Passerine migrants respond to variation in predation risk during stopover. Animal Behavior 69:1173-1179.

DeLong, J., Hoffman, SW. 1999. Differential Autumn Migration of Sharp-Shinned and Cooper's Hawks in Western North America. The Condor 101:674-678.

Gill, FB. 2007. Ornithology (Third Edition). W. H. Freeman and Company, New York, NY, USA.

Kjellen, N. 1992. Differential Timing of Autumn Migration between Sex and Age Groups in Raptors at Falsterbo, Sweden. Ornis Scandinavica 23:420-434.

Mueller, HC., Berger, DD. 1967. Wind Drift, Leading Lines, and Diurnal Migration. The Wilson Bulletin 79:50-63.

Titus, K., Mosher, JA. 1982. The Influence of Seasonality and Selected Weather Variables on Autumn Migration of Three Species of Hawks through the Central Appalachians. The Wilson Bulletin 94:176.184.

Smith, JP., Farmer, CJ., Hoffman, SW., Kaltenecker, GS., Woodruff, KZ., Sherrington, PF. 2008. Trends in autumn counts of migratory raptors in western North America. The State of North American Birds of Prey, ed. by K.L. Bildstein, J.P. Smith, E. Ruelas I., vol. Series in Ornithology(3), pp. 217-252, American Ornithologists' Union and Nuttall Ornithological Club, Cambridge, MA.

Viverette, CB., Struve, S., Goodrich, LJ., Bildstein, KL. 1996. Decreases in Migrating Sharp-shinned Hawks (accipter striatus) at Traditional Raptor Migration Watch Sites in Eastern North America. The Auk 113:32-40.

Passerine migrants response to predation risk

I am back again with more bird migration research. This paper is focused more closely on the predator prey relationships, specifically on the response of prey species to the abundance of predators. This is somewhat related to my research on the related timing of migration between predator species and prey species. I am not sure if I can specifically use this paper as it is more behavioral at an individual level as my work is more focused on population level reactions. It's interesting none the less.

CIMPRICH, D., WOODREY, M., & MOORE, F. (2005). Passerine migrants respond to variation in predation risk during stopover Animal Behaviour, 69 (5), 1173-1179 DOI: 10.1016/j.anbehav.2004.07.021

Predator-prey interactions at migratory stop-over points is interesting for a number of reasons. The prey birds must manage the risk of predation against their need for large quantities of food to support their journey. Complicating the situation is that they are in unknown territory with unknown risks. The shrubs may be different, the food may be different, and even the predators may be different.

The researchers studied two prey species (Blue-grey Gnatcatchers (Polioptila caerulea) and American Redstart (Setophaga ruticilla)) and one predator species (Sharp-shinned Hawk (Accipiter striatus)). The "Sharpie" is definitely one of my study species, but the prey mix will be different for my study due to geographic location. Their study used both observational techniques and manipulative techniques in an interesting way. For the manipulative they created a balsa wood airplane which resembled a sharp-shinned hawk and launched it 4m over the heads of some prey birds under observation. This produced consistent reactions to real sharpies flying low over the foraging area. This allowed the researchers to add to the natural migration rate of Sharpies over the site and measure the response.

The results indicate that both prey species moved deeper into the woods as the number of predators flying over per hour increased. The Blue-grey Gnatcatchers also moved at slower rates during higher volumes of predators. It did not appear that the increased presence of predators decreased their foraging rate significantly. This illustrates that the predators changed how they foraged, but not the rate, answering the question on how they balance the risk with their urgent need to build their fat stores.

While this might to be directly useful in my work, the paper did present a couple of interesting references to other papers which promise to be quite helpful. The continued exposure to field and statistical methods is also helping me get my mind around the daunting task ahead of me.

science, ornithology, research

Cold Front Effects on Migrating Raptors

I have continued my reading of research papers as background material for my upcoming research on the related timing of fall migration of avian predators (accipters) and avian prey (songbirds). A couple of papers were duds and not worth writing about. This one however is a very good paper and very relevant to my work.

Paul E. Allen, Laurie J. Goodrich, & Keith L. Bildstein (1996). Within- and Among-Year Effects of Cold Fronts on Migrating Raptors at Hawk Mountain, Pennsylvania, 1934-1991 The Auk, 113 (2), 329-338

The paper looks to answer what effect the passage of cold fronts has on raptors during the fall migration. Using 55 years worth of data from migration monitoring at Hawk Mountain Pennsylvania and weather data from the National Oceanic and Atmospheric Administration, the researchers had ample data to work with. In addition to looking within single years for the correlation, they also used multiple year data to illustrate that the storm fronts were not just making the hawks easier to count.

The research illustrates that the passage of storm fronts has a significant impact on the number of hawks passing by Hawk Mountain. This increase was significant in 13 of the 14 species being monitored with the Rough-legged Hawk (Buteo lagopus) being the only exception. The various classes of raptors behaved differently relative to the storm front, and aligned into three different response groups. The first group (Bald Eagle (Haliaeetus leucocephalus), Ospreys (Pandion haliaetus), Merlins (Falco columbarius), American Kestrels (Falco sparverius), and Peregrine Falcons (Falco peregrinus)) peaked in numbers on the day of the cold front passage. The second group (Golden Eagles (Aquila chrysaetos), Sharp-shinned Hawks (Accipiter striatus), Cooper's Hawks (Accipiter cooperii), and Northern Goshawks (Accipiter gentilis)), which includes my three study species (the accipiters), peaked the day after the storm front passed. The last group, the Buteos (Red-shouldered Hawks (Buteo lineatus), Red-tailed Hawks (Buteo jamaicensis), and Broad-winged Hawks (Buteo platypterus)), peaked 1 to 3 days later. This can be explained by the various flight patterns of the birds involved (altitude, soaring, etc).

To illustrate that the weather patterns were not simply making the hawks more visible to the observers, the researchers compared the number of cold fronts occurring in each migration season (range 10-20) with the total raptors counted each year and found that there was little correlation in the variability. This analysis strengthens the findings that cold fronts do have an effect on the daily migration volumes of raptors.

As with each of these papers I walk away with more questions than answers. The first question is whether the data from the Idaho Bird Observatory agrees with their conclusions. Do weather impacts in the western United States have similar impact to the east? What are the effects on migrating songbirds? I will have to answer these questions to complete my work. At least my three predator species (Sharp-shinned Hawks (Accipiter striatus), Cooper's Hawks (Accipiter cooperii), and Northern Goshawks (Accipiter gentilis)) each reacted consistently to the storm front, this will make it easier than if they each reacted differently.

I will be working this summer at the Idaho Bird Observatory for songbird banding and hawkwatch, both relevant to my research. In addition, I will be utilizing 13 years worth of data collected at the site. I will also spend some time banding raptors and owls.

Snakes on the Bike

I've been riding mountain bikes in the Boise foothills for 20 years. Each year I see a couple of snakes out on the trail. This year it seems as if I have seen more than all other years combined. I'm not sure if my timing is different, or what the possible explanation might be.

Three Snake Day. Last Tuesday on one 17 mile ride, we found three snakes - one Gopher Snake (Pituophis catenifer), one Racer (Coluber constrictor), and one Western Terrestrial Garter Snake (Thamnophis elegans). Generally the Gopher Snake, which many locally refer to incorrectly as a Bull Snake, is the most commonly seen in the foothills. Yesterday I found another Gopher Snake and saw two other snake trails across the path. Once last year we found that these snakes will hiss loudly when cornered as I stopped just short of running one over.

Rattler! Today we would also find a young Gopher Snake, but the most exciting was the Western Rattlesnake (Crotalus oreganus)! The snake was lying across the trail. I braked so as not to run it over. I originally thought it was a Gopher Snake. The snake was not in a hurry to get out of the way. I ended up stopping right next to it. That's when I noticed the long set of rattles on its tail. He/she was using them and coiling up. It was about 18 inches away! Yikes. I informed the stoker to power away. The snake started making striking motions toward the bike, inches from Karyn's leg. We pulled out of the way and let the people behind know to give the snake a wide berth. Hopefully, he/she made it away from the bustle of the busy trail.

BTW, the Digital Atlas of Idaho provides great reference information for the species of Idaho.

Update 6/3: A reader informed me that the scientific name of the rattlesnake has changed from Crotalus viridis to Crotalus oreganus (see comments).

idaho, mountain bike, reptiles, snakes

Owls, Woodpeckers, and other ilk

This week, in my down time between spring semester and the upcoming summer semester, I volunteered to help a graduate student friend of mine with his research. His research is focused on Woodpeckers presence as a predictor for Owl presence within the Boise National Forest. A couple months back I volunteered on the Owl survey portion of the research. This week is the woodpecker portion.

One detail that I wasn't fully up to speed on was that I would be doing fully species surveys and not just woodpecker surveys. Ouch. I had been studying the songs and calls of woodpeckers, but the whole list of species? The day before my departure I spent a good deal of time studying. While my study time was very helpful, it was inadequate for the task of identifying every species.

The work consisted of getting up very early on three mornings and trying to survey as many spots as possible before 11am. The first morning we left from home, but camped the other two evenings close to early survey points.

We surveyed the first two locations together to get a feel for the process. I didn't do too bad with only a few unidentified species. Apparently it was good enough, so I was sent out on my own. The real need is to get the woodpeckers correct and to get the general species richness from the area. That is fairly easy to do, even if you cannot identify every bird. It is always a very educational experience to spend time in the field with a knowledgeable birder and scientist. This trip was no exception. One afternoon we also performed vegetation analysis of one of the points. This was a fairly detailed process taking over 4 hours. Hmm. 90 points, 4 hours each... Micah will be one busy fellow. We also fit in a mountain bike ride! woo hoo! I wasn't a very good guide as I took a wrong turn so we descended a gravel road instead of a cool trail. Anyway, it was fun.

There were a number of special sights in the field:

• Mating Sandpipers. At my first solo survey location two Spotted Sandpipers mated on a log during my survey.

• Mating Western Bluebirds. At lunch two Western Bluebirds (life bird for me), landed on a nearby post and mated. Another pair mated next to our camp that evening!

• Calliope Hummingbird "J" Dance. Our vegetation analysis was disturbed by a male Calliope Hummingbird courting a female. She was perched on a nearby tree. He would fly high in the air, dive down at fully speed and pull up just before hitting the ground. While doing so he would make a snapping sound with his wings at the bottom. This was less that 10 yards away. He repeated the display three or four times. He then hovered in one place, turning 90 degrees every 10 seconds or so. She must not have been impressed as we saw him later perched looking around for her. We would see another "J" dance that evening in camp and another at one of my survey points.

• Woodpeckers. While none of my survey spots had woodpeckers on the first day, three of my ten spots did on day 2, and three of my nine spots on day 3. Three spots had Hairy Woodpeckers, responding aggressively to played recordings we use during the survey, and one spot had Red-naped Sapsuckers. The other two locations had Northern Flickers. I joined Micah for his last location of day 2. This site produced Red-naped Sapsuckers, Hairy Woodpeckers, and Northern Flickers. Cool.

• Drumming Grouse. As I mounted my mountain bike at 5:40am on day 3 for the ride to my survey point, I noticed a Ruffed Grouse drumming nearby.
  

• Life birds. Spending time with experts always seems to produce more life birds. Mine for this trip - Western Bluebird, White-Breasted Nuthatch, and Cassin's Vireo.

During my summer term I hope to spend a little time volunteering with another friend performing research on American Kestrels. Then there is my own migration research. My field work for that begins July 15th.

Not so Wild in the Wilds

Here is the third and final summary of our continued adventures in Yellowstone. The first part of the story is here - The Tyranny of Nature's Plan, part two is here - The Struggle for Existance.

Our last few days in Yellowstone came with mixed experiences. We had some great wildlife viewing experiences, hiked beautiful trails with little or no people, but mostly dealt with the crowds of people flooding the park. Lesson: Do not spend memorial day in the park! For the first time ever, I was happy to exit the park. Lesson 2: if you are willing to hike more than a mile, there are vast wide open spaces with no one else around. The good news for the wildlife is that most of the people visiting the park are too lazy to get off the road.

Yours truly scouting the local avifauna.

The highlights of our remaining day included numerous views of the druid and cottonwood wolf packs, watching a black bear and her two cubs each evening, and hiking trails and not seeing a soul (until within a mile of the road!).

Druid Pack Wolf on Carcass.

Taking a Bone back to the Den.

Coyote's Turn on Carcass.

"You can't fix stupid". This was a quote from a fellow wolf watcher as we watched two guys park their car in a "no stopping zone" and walk up the hill to get a better photo of wolves. Three yearling wolves had a cow elk surrounded and appeared to be looking for her calf. These idiots walked to within 30-40 yards of the wolves. Some day there will be a wolf/human interaction and it will most likely be the result of stupidity like this. Of course, they will blame the wolf and not the individual making the poor decision. The two pretended to not speak English in poorly phased and poorly accented Spanish. Another reason to avoid the park on Memorial Day weekend.

In another blatant disregard for the wild of wildlife, here is a view of what a badger in a badger den has had to deal with for the past week. These guys are less than 10 yards from the den. Morning to night.

Badger paparazzi.

In all, up to this weekend, it was another fabulous trip to the park.

Moose near Soda Butte.

Savannah Sparrow.

The Struggle for Existance

Here is a summary of our continued adventures in Yellowstone. The first part of the story is here - The Tyranny of Nature's Plan.

The flight of the Eagles. Tuesday evening present a spectacular showing of eagles. Our friends pointed out the Bald Eagle nest where we could see the new hatchlings. Within a one hour period we also witnessed a first year, second year, third year, and adult Bald Eagle flying overhead. Most visited the carcass in the Lamar Valley. These eagles were joined by a juvenile and adult Golden Eagle, numerous Red-tailed Hawks, and the ever present Ravens.

Swim for your life. Wednesday morning after watching the Agate wolf pack, we moved on to watch the Druid wolf pack. The alpha male, another adult, and two yearlings were just leaving yesterday’s carcass. We watched as they made their way up river. At one point the alpha male swam the raging river. The river is high and muddy, with trees floating down. He was swept far down stream. The other adult made it most of the way across before turning back. She just pulled herself out of the river when she was attacked by a lone elk. The elk probably had a calf hidden nearby. The wolf had no fight left and ran from the elk. The two yearlings also tried the river, but turned back as well. They decided to chase a small herd of elk, but they too were too worn to put up a real chase. All three wolves chose to dodge vehicles on the highway instead of taking another turn at the river. An afternoon hike along the rim of the Yellowstone River provided some great bird watching as we looked down on Osprey & White-throated Swifts as Mountain Bluebirds joined us on the ridge.

Yearling wolf splitting an elk herd.

Yearling Wolf from Druid Peak Pack.

Mountain Chickadee with some attitude!

Three’s a crowd. While at Dorothy’s Knoll in the Lamar Valley we looked up to see three wolves marching through the sage brush. Behind them were three coyotes chasing after them. Behind the coyotes was a large grizzly bear! All in the scope at the same time! My read is that the wolves were out on a hunt, the coyotes simply wanted them out of their territory, and the bear wanted to steal anything that the wolves took down. Grizzlies commonly steal carcasses that the wolves kill. As they made their way across the hillside, the bear had to stand up on two feet to see which way the wolves were headed and then run to catch up. He did this three times while we were watching. The last time the bear raised up he turned and ran in the other direction. The coyotes scattered. The wolves were in pursuit of the bear. They chased him up and over the ridge before returning to the valley. The coyotes tried to get the wolves to leave, but they were simply ignored. The wolves bedded down on the hillside and stayed there until dark, and who knows how much longer.

Pika (photo by Karyn).

Bloat and they will come. The action returned to the scene of the dead bison mentioned 5 days ago (in a previous blog post). The bison had died of unknown causes. Her calf stayed with her trying to nurse until finally dying of starvation. We were amazed that no animals had fed on the bison. Apparently coyotes had tried, but could not break open the carcass. That takes a wolf or a bear. After sitting in the sun long enough, it finally attracted the right attention. Apparently wolves were on the carcass last night and a grizzly this morning. We missed that, but got there in time to watch 5 wolves from the Blacktail Pack, including the famous wolf 302, having their fill (previous years blog posts mention wolf 302 and he is featured in a few National Geographic films on wolves). The pack looked thin and rough, they did not appear to be doing well. Later reflection would indicate that these wolves have mange. This puts them and their puppies at risk if they are not well fed. They were joined on the carcass by the ever present Ravens, a Turkey Vulture, Bald Eagles, a Golden Eagle, and some coyotes, but not all at the same time. One bison will feed a lot of mouths and more importantly a lot more puppies and chicks.

Blacktail wolf pack on Bison carcass.

The Tyranny of Nature’s Plan

I borrowed the title from one of my favorite lines of a Jakob Dylan song. It’s very appropriate for what you can experience in Yellowstone National Park this time of year. Yellowstone, like no other place nearby, allows nature to play out in front of you. It brings excitement, fascination, life, sorrow, and death. In each of life’s struggles, there are winners and losers. Today’s winner might be tomorrow’s loser.

Finishing up my finals this week, my internal zugenruhe (migratory restlessness) couldn’t wait to get to Yellowstone. We left early Friday morning, but was delayed as I accidently backed into someone in the parking lot. No injuries and only minor damage. It only slowed us up about an hour.

We stopped in to Centennial Marsh on the route. This is a great birding place in South-central Idaho. Lots of water birds here – Ducks , Geese, Shorebirds (Avocets, Stilts, Phalaropes, etc), Sandhill Cranes, and a new life bird for me, a somewhat lost Eastern Kingbird. The Swainson’s Hawks and American Kestrels were also plentiful. From there we headed straight into Yellowstone.

Eastern Kingbird.

Black-necked Stilt.

We had reservations at Madison campground for the first night. We had seen wolves here before, but they are not very predictable. In fact, the wolf’s photo at the top of my blog was taken on a hike from the campground. We wouldn’t see any on this day. We did hear both Coyotes and Great Horned Owls during the night.

The next morning we headed off for the northern range of Yellowstone where most of the wildlife action usually is. Driving by Nymph Lake Karyn noticed an elk standing in the water. This being somewhat rare unless a predator was present, we turned around and found a spot to check it out. The elk was clearly disturbed. Further investigation revealed three wolves on the shore, mostly bedded down. The elk had a significant gash in her front shoulder. The wolves clearly had her before she made it to the water. Now it was simply a stare down. The wolves were in no particular hurry, essentially sleeping on the shore.

After about 30 minutes, the black wolf waded out into the water after the elk. The elk ran into the deeper water where the wolf lost its footing. The wolf turned and the elk attacked chasing him instead. He tucked his tail and lowered his head running until it got on better ground. He then turned and reversed the process. The chase went back and forth six times, the advantage shifting from one to the other. The following highlights some of the sequence.

In the end, the wolf returned to the shore and bedded down with the other wolves. The elk stayed in the water. We watched for two more hours, the stalement unchanged. It amazes me when you hear the stories of “the wolves decimating the elk”. They always sound so one sided. I have been watching wolves for 10 years and have yet to see a take down. Clearly they kill and eat elk, I have watched them feed on many carcasses, but I have also observed many situations like this one, where the wolves come up empty. Who knows how this one untimely played out, in my opinion it could have gone either way.

Heading toward the Lamar Valley, we found another of nature’s stories being played out. A female bison had died of unknown causes, but apparently not from predators. Her calf, likely only a few weeks old, was trying to nurse. The calf’s fate is sealed, it will die by predation or by starvation sometime in the next day, two at the most. (Update: 3 days later found the calf dead - starvation was the fate).

We decided to camp at Tower campground. It is near the center of the action. Other choices would be Mammoth or Cooke City. Slough Creek campground is our favorite, but it hasn’t been opened yet. Finding our site, we took a hike up behind the campground. We found a number of birds present. The sound of Ruby-crowned Kinglets filled the air. At one point we were staring down a Blue Grouse. He was drumming, it was barely audible as the sound is at the low end of human hearing.

Blue Grouse.

Near the top of the trail we started seeing bones, lots of them. We became much more aware of our surroundings as carcasses are dangerous places to approach. Both wolves and grizzlies will aggressively defend a carcass. No signs of either. But there were lots more bones, too many for a carcass. Then we found skull after skull. It dawned on me that this is likely the dumping ground by the park service for roadkill. We checked it out, but didn’t stay long.

The evening trip into the Lamar Valley would fail to produce wolves. We did get to watch three grizzly bears and took a few good photos as one swam the river, chased some bison, then moved down the valley. The bison mounted a hearty defense, the males grouping up to rush the bear. The bear wouldn’t have a chance to get a calf in this herd. This will be a tough day to beat.

Grizzly Bear.

Before our alarm went off the first two vehicles of wildlife watchers left the campground. We were clearly behind the game. We will have to remedy that tomorrow… We headed into the Lamar Valley in the hopes of seeing the Druid Peak wolf pack. We were not disappointed. One member of the pack was heading down from an apparent carcass toward the parking lot where we were watching from. The den site is on the hill behind the parking lot. Thus, this particular vantage point is fairly popular as most of the to/from trips to the den pass nearby. This wolf passed fairly close, enabling a few great photos.

Druid Peak Wolf.

Later we would see a few other members in the area. The alpha male was found bedded down near a carcass in the middle of Soda Butte Creek. Many of the wolves were visiting the area, but not the carcass itself. That was left to the Common Ravens, Black-billed Magpies, and a Golden Eagle. A number of Grizzly bears were in the area. High on a ridge above the valley was a group of Bighorn Sheep. While there was not the same excitement as yesterday’s exchange, it is amazing to be in one place watching wolves, bears, antelope, bighorns, eagles, etc. The scene also allowed us to catch up with some of our wolf watching friends that we only see in Yellowstone.

Today’s hike took us to Trout Lake and beyond to Shrimp Lake. We didn’t see trout or shrimp! We hoped to see otters, but struck out there as well. The upper lake was still mostly frozen. The lower lake (Trout) was occupied by several pairs of Barrow’s Golden-eye. At one point we heard a woodpecker in the forest. We had to hunt it down to get a positive ID. I am in the process of learning the woodpeckers by sound so that next week I can perform woodpecker surveys for a graduate student friend of mine. This one would be a Hairy Woodpecker. Earlier in the day I properly identified a Red-naped Sapsucker by sound. While watching the Sapsucker we noticed a Mountain Bluebird perched at a nest cavity in an Aspen tree. He flew to a nearby branch. A Northern Flicker jumped in and claimed the cavity. Not sure who it belonged to previously, but it was now in the possession of the Flicker. For a secondary cavity nester like the bluebird, finding a vacant nest is critical. Another of nature’s ways. We wished him luck. A few minutes after our hike we watched a grizzly come out of the trees a couple of hundred yards down the road from where we were just hiking! Hmm.

After lunch it was back to the wolves and grizzlies in the Lamar. Not usually seen mid-day, but today was an exception for both. We would see lots of both. After a few wolves crossed back and forth across the road, apparently shuttling food to the puppies at the den, the photographers decided to line up right at the crossing. Of course, this prevented the wolves from crossing. They tried a number of times to cross, but failed. They eventually circled far around the corner and crossed. From our vantage point we could watch it all. Who knows what the people were thinking. They each had 600mm lens, backing off 100 yards would have provided great shots and not interfered. That evening was beautiful as we watched multiple grizzlies in the Lamar Valley.

Monday produced another beautiful day. The Druid Peak pack were still somewhat visible near their den sight. We moved to Slough Creek, but didn’t see any action. Instead we opted for a morning hike in the marsh. I specifically hoped to see an American Bittern. We were not disappointed. Another new life bird!

American Bitter.

A beaver was working the local ponds, one of the new residents that recolonized after the wolves returned. Lots of ducks, phalaropes, blackbirds, and sparrows filled in the scene. High on the hill above was a pack of wolves, one black and three grey. We watched them mill around the old den site of the Slough Creek wolves. While watching, one elk started walking up the mountain toward them. I couldn’t believe how close she was getting. It was later hypothesized that this elk had a calf hidden in the area. We are just entering calving season. We didn’t observe any direct interaction, now did we see a calf. Another of natures stories that we won’t know the end to. Did the wolves eat or did the calf live…

The afternoon hike took us in search Harlequin Ducks at the confluence of the Lamar and Yellowstone rivers. Once again we were not disappointed.

Harlequin Ducks.

With luck like this, I should definitely set my sight higher.

Tuesday brought many lessons about territory and resources. The morning began watching three separate grizzlies interacting with bison. Apparently those calves look mighty tasty. The bison would have nothing to do with it. Either running away as a heard or chasing the bear as a herd. The herd instinct clearly helps the bison.

High on the ridge we saw the Druid wolf pack. They had come across some coyotes who were causing quite a ruckus. The coyotes had a den in the area. The wolves descended, dug up the den and killed at least 4 pups. There would be no litter this year for these coyotes.

We moved down the valley to Dorothy’s Knoll. Here we found a fresh elk carcass with three coyotes on it. While watching a lone wolf came in and chased the coyotes away. They put up a good fight, but 3 against 1 wasn’t enough. The wolf ate quite a bit before the coyotes returned with reinforcements. This time it was 4 on 1. The wolf could not cover all 4. They grabbed his hind leg numerous times, but if they held on he would have got them. The wolf gave up and moved across the valley. The coyotes returned to the carcass. On the way across the valley the wolf picked up a dead elk calf. He carried it to the river, swam the raging river with the elk calf in his mouth and climbed the mountain beyond. Amazing. By this time one of the Druid wolves found the carcass and fought off the coyotes. He too ate until the coyotes put up another assault to chase him from the carcass. He suffered more damage as he limped away.

Gray wolf (center) surrounded by 4 coyotes.

Later in the day at Floating Island lake we watched as a Barrow’s Goldeneye repetitively attacked another goldeneye couple. Apparently this was his lake and he did not appreciate intruders. He was dive under the water and attack them like a torpedo. Great stuff.

Weather effects on fall hawk migration

I have continued the background discovery process for my research project on songbird and accipiter hawk (hawks that feed on songbirds) migration patterns. A week ago I reviewed a paper on the differential timing of accipiter hawk migration. That particular paper provided a lot to think about and indicated that I may need a more complicated algorithm for my research. This week I found some time to review a paper on weather impacts on hawk migration. I am interested in the research as I will likely need to factor weather patterns as a variable in my analysis.

Kimberly Titus, & James A. Mosher (1982). The Influence of Seasonality and Selected Weather Variables on Autumn Migration of Three Species of Hawks through the Central Appalachians The Wilson Bulletin, 94 (2), 176-184

The paper focuses on the three hawk species migrating through the central Appalachian mountains. Only one of the three species is an accipiter (Sharp-shinned Hawk - Accipiter striatus), while the other two are Buteos (Red-tailed Hawk - Buteo jamaicensis, Broad-winged Hawk - Buteo platypterus), generally not predators of songbirds. The monitoring sites were located in western Maryland, with total migrating birds compared against Hawk Mountain in Pennsylvania. A number of weather variables were used including wind direction, wind speed, horizontal visibility, cloud cover and temperature. The study was conducted over a five year period - 1975-1979.

The paper found that the number one variable in the analysis for predicting migration was the date, followed by the time of day. These were far more significant than any other factors. In other words, when a bird begins a migration, it most likely just copes with the weather conditions as they are dealt. This is not a surprising find in my mind. Further, for the species of my interest, the Sharp-shinned Hawk - A. striatus, they found no significant interaction between wind speed or direction, although a general correlation of good visibility and tail winds was present. The Broad-winged Hawk - B. platypterus, had similar results with a general correlation with good visibility and strong favorable winds. Only the Red-tailed Hawk - B. jamaicensis, produced a significant result. They tended to favor light, opposing winds from the Southeast. These results conflict other findings cited in the paper.

The results seem somewhat logical to me. The Sharp-shinned Hawk spends significantly more time providing its other thrust, than the Buteos which are more dependent upon thermals and gliding. The thermals would be weather dependent, thus you would expect a more significant result for these birds. These results could simplify my work, although they raise more questions than answers. I do not believe this study is sufficient for me to remove weather from my model. I will have to study the other references cited.

Birding with the pros

On Sunday, while I could have been studying for my upcoming exams, I instead went birding with some friends. This was the right choice to make for many reasons. First, I ended up doing well on my exam anyway. Second, birding is just a lot more fun than studying. And lastly, I had an opportunity to go out into the field with some of the most skilled birders around. Not only did I see a lot of birds, over 60 species for the day including 3 life birds, I was able to learn a great deal from my guides. (A life bird refers to the first time you seen a specific bird species in your life).

We started by heading out to Black's Creek Reservoir. This area has been identified by our local Golden Eagle Audubon Society, of which I am a member, an Important Bird Area. On the way we spotted this Burrowing Owl. These are definitely a favorite of mine.

Burrowing Owl.

Arriving at the reservoir, Jay navigated the car through the mud trenches left by other vehicles when the water level was higher. Good news: no pushing this week! Among the sound of gunfire in all directions, official and unofficial shooting ranges nearby, we enjoyed some excellent bird watching. Lots of birds to be expected such as Great Blue Herons, American Avocets, Killdeer, other shorebirds, geese, ducks, and gulls. The highlight was seeing a few new life birds (Least Sandpiper and American Pipit) and getting side by side comparisons of a Least Sandpiper and a Western Sandpiper. I have to admit that I still have some studying to do before I could identify them on my own. From here we moved on to Indian Creek Reservoir.

Indian Creek Reservoir provided much greater diversity for us to see. Maybe because there was no gunfire? Anyway, here we saw a Great Egret:

Great Egret.

Also, Long-billed Dowitchers, Long-billed Curlews, Avocets, Marbled Gowits, all three Teal (Green-winged, Blue-winged, and Cinnamon), a large group of American White Pelicans, Double-crested Cormorants, Wilson's Phalaropes, Western Grebes, etc. The highlight here would be the new life bird - Semipalmated Plover. Once again, we had the opportunity for side by side comparison with a closely related Plover - the Killdeer. I feel more comfortable with my skills on identifying this bird now.

The rest of the evening we spent checking out other areas, looking for sparrows and warblers. We found a number of each. I am very grateful to my guides, Jay and Heidi, who invited me along, shared their knowledge, and were patient with my abilities.

More photos of the trip.

idaho, birds, birding

Differential Autumn Migration of Accipiter Hawks

I have been narrowing in on the specification of my undergraduate research project in Biology/Ecology. The current proposal is related to correlation of migration timing between Predators (Accipiter Hawks) and Prey (Songbirds) at the Idaho Bird Observatory. In the process of refining my research objectives and proposals, I have begun the review of relevant prior research. This is the first paper I have reviewed.

The two most relevant predator species for songbirds are the Sharp-shinned Hawk (SSHA) and the Cooper's Hawk (COHA). The chosen article analyzes the timing of migration between Sharp-shinned Hawks and Cooper's Hawk, differences between male and female migration timing, differences between juveniles and adults, and the differences from year to year.

John DeLong, & Stephen W. Hoffman (1999). Differential Autumn Migration of Sharp-Shinned and Cooper's Hawks in Western North America The Condor, 101 (3), 674-678

Its worth noting that one of the study sites referenced in this paper is likely on the migration flyway south of the Idaho Bird Observatory. Thus, the populations being monitored at that site is likely part of the same migratory population that I will be studying.

The authors reviewed data from two hawk banding sites, one in New Mexico and one in Nevada, over a five year period (1992-1996). They only used banding data due to the unreliable sexing of non-captured birds. Banded birds are captured, where non-captured birds are only observed flying over the monitoring site. Most of the results analyzed are statistically significant, with a couple of non-significant points dealing with the year to year comparisons at one of the monitoring sites.

The authors discovered the general migration order to be juvenile females, juvenile males, adult females, then adult males. The Sharp-shinned Hawks had greater spread in these classes than the Cooper's Hawks. The Sharp-shinned Hawks on average came through the monitoring sites later in the migration season than the Cooper's Hawks.

There are a number of possible explanations for these results provided in the discussion section of the paper. The main question is whether the birds leave their breeding area at the same time. Most likely the juveniles leave early. Whether this is based on their decreasing ability to capture food, or for some other reason is not known. The sex differences could be related to the females leaving the breeding site earlier or the females simply migrating at a faster rate. Since the females are larger than males (reverse sexual dimorphism), they fly faster and have greater endurance. This could be the reason for the differential timing at these southern monitoring stations. It is also possible that the females leave early as their prey base may be less available than the food base for the smaller males. A similar explanation could be used for the differences between the two species. The smaller species (Sharp-shinned Hawk), could be flying slower or could have stayed longer due to different prey base availability. We just don't know. It would be interesting to know if the differential timing is the same at more northern monitoring stations like the Idaho Bird observatory. That could be a whole study in itself.

The results of this paper clearly complicate my potential project. I now must consider the predator species (SSHA or COHA), male/female, and adult/juvenile populations differently. It's definitely a fascinating area of research. I will post additional article reviews as I read them.

wildlife, birds, migration, research, peer reviewed research

Dead Week Birding

While all my schoolmates were in class, and my old colegues were at work, I was out birding!! One advantage of taking 4 labs this semester is that during dead week (this week), when most of my labs were done, it seemed like I have nothing to do. There is that research paper due, but I finished it weeks ago. I could start studying for next week's exams, but it just doesn't seem right (actually I did end up studying today). Birding was a much better idea.

Karyn and I headed out to our favorite spot, Hull's Grove. It's our favorite as we can walk from the house. It is about a 4 mile loop from the house, passing two wetland ponds and plenty great bird habitat.

The first stop was the "lower pond". Here we found the usual array of Red-winged Blackbirds, Mallards, an unusual group of Canada Geese, and one of the resident Pied-billed Grebes. There's a pair of Grebes in the pond, so we are hoping for chick photos soon. A narrow trail from here produced many of the day's highlights. A Macgillivray's Warbler, a Yellow Warbler, a Black-headed Grosbeak, and this Calliope Hummingbird. All first for the year!

Calliope Hummingbird.

Hiking past here up onto Chickadee Ridge we could see the Red-tailed Hawk chicks in the nest. There appears to only be two this year. It's possible there was a third one hidden in there. Bank Swallows were flying near our heads. They have definitely moved into the sand cliffs for the year. We stopped at the Cooper's Hawk nest that we discovered a few weeks ago (photos earlier on my blog and here). It looks like incubation is continuing. No sign of chicks at this time. We found the Great Horned Owl family happily in the trees above the "Owl's Roost" trail. Stories about their fledging can be found here and here).

Great Horned Owl chicks and 1 adult.

Great Horned Owl chicks.

We couldn't ignore the song of the House Wrens at the base of the owl tree.

House Wren.

House Wren singing.

Believe it or not, the House Wren is a life bird for me. Woo hoo! Last on the tour of nests was the American Robin nest back near the lower pond.

American Robin nest.

What a great day for a casual outing. One life bird (House Wren), and nine year birds (MacGillivray's Warbler, Yellow Warbler, Bank Swallow, House Wren, Calliope Hummingbird, Lesser Goldfinch, Bullock's Oriole, Black-headed Grosbeak, Lazuli Bunting).

idaho, boise, birds, birdwatching

Stuck in the mud!

Saturday brought our final field trip for our Ornithology class. The destination was Centennial Marsh in south central Idaho. This is one of my favorite birding locations and is highlighted on the Idaho Birding Trail.

I awoke to the sound of rain, fairly heavy rain for our area. I hoped it wouldn't dampen our prospects too significantly. The group, down a little from our full class, piled into the two vans to head out. The first destination was Indian Creek Reservoir, another location on the Idaho Birding Trail. The road in would prove a little too muddy for the school vans, so we retreated before getting stuck. We moved on toward Mountain Home Reservoir (you guessed it, another Idaho Birding Trail Feature).

The rain decreased to a drizzle as we arrived at the reservoir. There were many shore birds present with a number of new species for my year list. The highlights American Avocet, Yellow-headed Blackbird, Black-necked Stilt, Eared Grebe, Long-billed Curlew, Long-billed Dowitcher, and Western Grebe, among many other less notable species. We loaded up an headed on toward Centennial Marsh

Upon arriving at the Marsh, the access road we planned to use was a little sloppy. We once again retreated. It looked as if the marsh would not be an option for us. There are lots of other wetlands in the area, so all would not be lost. We did find an amazing number of Swainson's Hawks.

Dark morph Swainson's Hawk.

Swainson's Hawk in nest tree.

Another Swainson in another nest tree.

Near one wetland, we discovered just how soft the shoulder of a wet road can be.

Shhh. Don't tell the University!

We scavenged wood from a nearby field and all tried to push, to no avail. We flagged down the first vehicle to drive by. It just happened to be a graduate of the raptor program at Boise State who had taken classes from our professor! What luck. He had a tow rope and pulled us out.

Towing the van.

As if this was not enough of an adventure, I talked the professor into attempting the other access road to the marsh. He agreed to give it a shot.

The second access road was in better condition, so we would get to the marsh after all. The road through provided a number of great species.

Long-billed Curlew

Northern Shovelers(larger) and Cinnamon Teal (smaller).

American Avocet.

American Kestrel eating lunch.

Wilson's Phalarope.

Willet.

Marbled Godwit.

But the adventure was not over yet. I want it noted that my suggestion was to use the other access road to get to the marsh, not to complete the loop. Anyway, the birding just kept getting better and better. On the back side of the marsh, the road was getting sloppier. The lead van made it through ok, but on a short rise, our van could not climb the hill. We were stuck again! Five of us piled out of the van and started to push up the hill. It was very slippery for us to get traction as well. When the van would slide to the side one would go to the side and push it back onto the center of the road. The people in the other van, being a few hundred yards up the road, looked on in amusement. Slowly but surely, we pushed the van over the hump. Clearly we need to be more prepared next time. Maybe take a tow rope, maybe wear better shoes for pushing than Katie was wearing!

Katie's foot!

That would be the end of the major excitement for the day. There were still more bids to see along the way. In all it was a great trip!

Sandhill Crane.

idaho, birds, birding, centennial marsh

Post-fledging challenges

A few days ago I wrote about the fledging of our local Great Horned Owl chicks. Later that night Karyn and I returned to see if we could watch the chicks flying. What played out was a more interesting tale.

We arrived to find the adult female owl feeding two of the chicks back in the nest hole.

Adult Great Horned Owl feeding young.

The youngest owlet was not at the nest, but was down on the sand instead, trying to get to the food. He/she was calling constantly.

Youngest Great Horned Owl chick.

Apparently not knowing how to fly to the hole, he/she was attempting to walk there.

The remaining steps back to the nest hole were apparently too much for the owlet. He/she slipped off of the ledge.

It would not appear as if this chick would be getting dinner tonight. One of its siblings did fly down to the visit for a moment, possibly to provide encouragement, before flying back to the nest hole. As the light diminished, the owlet was again attempting to walk back to the nest hole.

We don't know if he/she got dinner that night, but the next evening we found all three owlets safely back in the nest hole.

idaho, boise, birds, owls

Fledging!

As I prepare for our last Ornithology class field trip tomorrow, Karyn and I headed out to check on the Mallard chicks in the upper Hull's Grove pond. Last weekend we observed a female Mallard escorting her 12 chicks over to the water. Yesterday we could only find six chicks remaining. I have been documenting them in my field journal that is due to be turned in on Tuesday. We thought we would go check out the ducks to see if there was anything new to write about.

On the way there we passed the Great Horned Owl nest. We looked in but didn't see any chicks. Their cave goes into the sandstone rock quite a ways and they are sometimes out of sight. We couldn't see them at all. We then noticed the two adults perched in a tree where we usually do not see them. Something was up. Following their gaze, we found the three chicks in some nearby sage brush.

Great Horned Owl chick.

Other two Great Horned Owl Chicks.

I hope they move to higher ground before any predators come out tonight.

Moving on to the upper pond, we could only find five of the original 12 Mallard Chicks. Its possible that there are more in the reeds. The chicks are using the entire pond and are getting around quite well. It only takes them 30 seconds or so to get to the other side. We watched as they rushed through the water in pursuit of prey.

Mallard chick.

I looked up from my vantage point to a female Red-winged Blackbird. I realized that I must be a bit too close to her nest. I decided to retreat and leave her in peace.

From Rob's Idaho Perspective

Tomorrow promises to be a great field trip to Centennial Marsh.

idaho, boise, hulls grove, birds, birdwatching

Accipiter cooperii

Cooper's Hawk

Other photos from today - Photos

Three's Company

This is the first time I have been by to check on the Great Horned Owl chicks in Hull's Grove. Wow, they grew fast. We observed the adults mating on a few occasions in early to mid-February. They were probably born mid March. In the last five weeks they have grown to nearly full size.

Great Horned Owl Chicks.

idaho, boise, birds, great horned owl

Peregrine Falcon Co-opting Canada Geese?

I just returned from a walk to downtown Boise for a few errands. I planned my route to pass by the building housing the Peregrine Falcon Nest (webcam). A few blocks before I got there I saw one of the Peregrines flying overhead. I assume it to be the female due to its apparent larger size, but I could be wrong. I didn't have access to the web cam to see which one was still on the nest! Anyway, the falcon was causing quite a stir in the local bird community as you might expect from such an efficient predator.

In watching her behavior, I noticed a few significant points. First, she was clearly on a mission. This has always impressed me about adult predators. The deterministic focus that comes from having to catch your own food to survive. The second thing I noticed is that she was focused on a pair of Canada Geese, but did not appear to be making any move to take one of them. I would have been surprised if she had due to their much larger size. She did fly low over the pair while they were on the edge of a three story building. This caused them to squawk loudly and fly to the next building. She circled around and flew low over them again, causing them to move on to a third building. She repeated the process again, but never made any specific move toward the geese.

I have a few hypotheses regarding what she was up to. The first is that she could have just been testing them. This is common for predators to regularly test their prey. The second, and more likely in my mind, is that she was trying to co-opt the geese in her hunt. By forcing the geese to fly and squawk then they become the center of attention for other birds. If any other prey birds focus on the geese, the Peregrine could take advantage of the distraction to grab the prey. Just a theory, but it definitely seemed like that is what was happening to me.

idaho, birds, peregrine falcon, predators