Ornithologi

A studio for bird study

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Published in the Journal of Raptor Research: Dietary Plasticity in a Specialist Predator, the Gyrfalcon (Falco rusticolus): New Insights into Diet During Brood Rearing

by Bryce W. Robinson

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I’m privileged to once again see a painting of mine don the cover of the Raptor Research Foundation’s quarterly publication, the Journal of Raptor Research. This time, however, is more special since the painting of a Gyrfalcon carrying its prey, an Arctic ground squirrel, corresponds to the feature article authored by myself and Travis Booms, Marc Bechard, and David L. Anderson.

Our publication titled “Dietary Plasticity in a Specialist Predator, the Gyrfalcon (Falco rusticolus): New Insights into Diet During Brood Rearing” details patterns we documented through implementation of nest cameras in 20 Gyrfalcon nests in 2014 and 2015. The largest camera study of nesting Gyrfalcons provided us with many new insights into the biology of this species, some of which we have already published, some that we have not. In this publication, we document a previously undescribed shift in prey use throughout the nestling period, from a diet of mostly Ptarmigan early in the season, to squirrel in the late season. This shift to squirrel is an important consideration on many levels. It highlights the nuances to Gyrfalcon prey use in Alaska, and the potential importance of squirrels in the later season for juvenile success and development. The apparent importance of squirrels also has implications for understanding ecosystem changes and how shifts in prey landscapes may impact Gyrfalcon reproduction. The stage is set to explore further.

Below are a few photos that describe the work that went into producing this publication. These highlight a some of the >750,000 nest camera images we collected from which the diet was quantified, as well as photos of the field work, and the people that made this effort possible. 

You can read our paper in the Journal of Raptor Research here:

https://bioone.org/journals/journal-of-raptor-research/volume-53/issue-2/JRR-15-58/Dietary-Plasticity-in-a-Specialist-Predator-the-Gyrfalcon-Falco-rusticolus/10.3356/JRR-15-58.full

Gyrfalcon nest 1

A female Gyrfalcon feeds nestlings. Image copyright Bryce W. Robinson/The Peregrine Fund.

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A female Gyrfalcon feeds her newly hatched nestling, alongside hatching eggs. Image copyright Bryce W. Robinson/The Peregrine Fund.

Female Gyrfalcon feeds nestlings Arctic ground squirrel

Female Gyrfalcon delivers an Arctic ground squirrel to nestlings. Image copyright Bryce W. Robinson/The Peregrine Fund.

Gyrfalcon nest 2

A female Gyrfalcon stands alongside c. 14 day old nestlings. Image copyright Bryce W. Robinson/ The Peregrine Fund.

Gyrfalcon nest 3

Parental care photo 1. A female (left) broods newly hatched young, reluctant to leave the nest at the male’s (right) arrival. Every Gyrfalcon would occasionally look at the camera, as seen here, but were otherwise unaffected by its presence. Image copyright Bryce W. Robinson/The Peregrine Fund.

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Parental care photo 2. In some cases, males were keen to participate in brooding and feeding young, as is shown here. In even fewer cases, the females were tolerant of this behavior. Image copyright Bryce W. Robinson/The Peregrine Fund.

Bryce and Gyrfalcon nest camera

Bryce W. Robinson sights in a nest camera at a Gyrfalcon nest. Image by Caitlin M. Davis.

Bryce rappelling into Gyrfalcon nest

Bryce W. Robinson rappelling into a Gyrfalcon nest in western Alaska. Image by Neil Paprocki.

Special thanks to the following people that made the field work happen

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John Earthman and Tinsel

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Neil Paprocki

Ellen in Gyrfalcon nest with nestling

Ellen Whittle holding a Gyrfalcon nestling in 2015.

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Mark Jeter and Ellen Whittle against an Alaskan landscape in 2015.

Special thanks to the institutions that made this work possible: Boise State University, Alaska Department of Fish and Game, and The Peregrine Fund

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Plectrophenax Illustration Featured in the Cornell Lab of Ornithology’s Living Bird Magazine: Complementary to an Article on the Birds of St. Matthew Island by Irby Lovette

by Bryce W. Robinson

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Plectrophenax spp., an illustration to complement the article detailing the 2018 Expedition to St. Matthew Island in Living Bird by Irby Lovette. Mckay’s Bunting (Plectrophenax hyperboreus; left), and Snow Bunting (Plectrophenax nivalis; right).

My involvement in the 2018 USFWS and USGS expedition to St. Matthew Island in the Bering Sea was as a field ornithologist, tasked with conducting surveys and collecting data on the abundance and nesting ecology of Mckay’s Bunting (Plectrophenax hyperboreus) and  the Pribilof Rock Sandpiper (Calidris ptilocnemis ptilocnemis). Of my four companions during my time on the island, two were from the Cornell Lab of Ornithology; Irby Lovette and Andy Johnson. Irby came along to assist Andy in filming and recording the birdlife on the island. He was also focused on experiencing the island to eventually write an article in Living Bird magazine. This article is now available online. It is a well written treatment of our experience, and details some of the fascinating history of the island as well. Also newly released to complement the article is a video, produced by Andy Johnson, that details some of the birdlife that we encountered on the island. It also highlights the purpose of our visit, and describes very well the feeling of being on this remote Bering Sea island.

I show up a few times in this video, in two occasions of which I am field sketching and painting. When in the field, I generally spend weather days or down-time sketching. I took the opportunity on a number of occasions and greatly enjoyed painting while in such an inspiring place. Irby took notice of my skills as an illustrator, and asked about my interest to paint an illustration to complement the article for Living Bird.

My drive to integrate illustration into my time on one of the most remote locations in North America enriched my experience. It is my hope that the illustrations I worked out on the island become part of a collection of products that complement the research we conducted. I hope these products provide a point of reference, and serve as a description for our experience. I envision an eager naturalist preparing for a trip to St. Matthew Island, as removed in time as we are to Fuertes and the short visit of the Harriman Expedition, exploring the various productions that have arisen and are yet to arise from our relatively short stay on the island. It is my hope that these products stir excitement and attention for this lonely location, support its preservation, and encourage further research into the life histories of its inhabitants.

Female Mckay's Bunting painting

Female Mckay’s Bunting. This is the painting I am working on in the video. It is now under the care of Andy Johnson in Ithaca, New York.

Mckay's Bunting pair illustration

A male and female Mckay’s Bunting painted on St. Matthew Island in 2018. This painting is now under the care of Irby Lovette at the Cornell Lab of Ornithology in Ithaca, New York.

Our month-long stay on the island was packed with incredible experiences and important discoveries. Such experiences are mentioned in Irby’s article, yet they truly only skim the surface. Over the next year or two, more products will come forward from our short stay on the island, so please stay tuned.

The Living Bird article on the birds of St. Matthew Island written by Irby Lovette can be found at the link below:

Birds of St. Matthew Island, the Most Remote Place in the United States

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The five inhabitants of St. Matthew Island in summer 2018. Left to right: Rachel M. Richardson, Steph Walden, Bryce W. Robinson, Irby J. Lovette, and Andy S. Johnson.

 

Bearded Vulture Illustration for HawkWatch International Shirt Design – Support Worldwide Vulture Conservation

by Bryce W. Robinson

Bearded Vulture

I was given the opportunity to provide a t-shirt design for HawkWatch International featuring the Bearded Vulture. The design and shirt are meant to both raise awareness and support for the important conservation science work of HWI focused on Old World vultures. Old World vultures are facing a myriad of threats that are impacting populations, to the point that most face extinction. Please, learn more about the work of HawkWatch International and consider helping in any way you can. Visit their website to read about the vulture work, and more.  

Click on the photo below to purchase a shirt, and support vulture conservation.

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Alaska Department of Fish and Game 2019 Conservation Stamp Featuring The Golden Eagle – Aquila chrysaetos

by Bryce W. Robinson

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Support the conservation of Alaska’s wildlife through the purchase of the 2019 Alaska Department of Fish & Game Conservation Stamp!

I had the pleasure of creating this years conservation stamp, highlighting one of Alaska’s most important avian predators, the Golden Eagle (Aquila chrysaetos). Biologists with ADF&G, such as Travis Booms, are currently working on research that aims to learn more about Alaska’s eagle populations and the threats they face, to ensure that this captivating species remains a fixture of Alaska’s wilderness.

To purchase a stamp, and learn more about the various conservation research conducted by Alaska Department of Fish & Game, visit their website.