Thursday, June 25, 2009

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!
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.

Friday, June 19, 2009


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

EducationYou often talk about school and learning.141.57
Occupation & work You talk a lot about jobs and your work. 84.26
Upward motionYou often make references to physically upward movement. Like upstairs, climb, etc.55.23
Past tenseYou tend to talk about the past.43.47
MetaphorsMany of your tweets contain metaphors.10.3
SensationsYou tweet about your various senses often.7.81
Physical referencesYou often talk about the physical characteristics of things.7.19

Primordial, Conceptual and Emotional Content

Temporal References111.32
Constructive behaviors45.09
Visual sensations24.48
Cold sensations16.89

Sunday, June 07, 2009

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.

Friday, June 05, 2009

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).


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.


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

Background Research

IBO data collection

Core analysis


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).

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.

Tuesday, June 02, 2009

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.

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Monday, June 01, 2009

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.