Ornithologi

A studio for bird study

Tag: nest

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

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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.

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

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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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Just Published in Avian Conservation and Ecology: Nest Box Use During the Non-breeding Season

by Bryce W. Robinson

 

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Caitlin just published an excellent paper detailing nest box use in the non-breeding season in Idaho.

This publication is an important contribution because it discusses patterns in nest box use during a period that has received little attention. Additionally, because nest box programs are engineered to supplement natural cavities to saturate an area with nesting habitat geared to benefit species, a full understanding of its impacts throughout the yearly cycle is important. This paper not only reports how nest boxes are used in the non-breeding season, but illustrates some possible negative impacts as well. Such impacts are primarily associated with the variable thermodynamic nature of nest boxes relative to natural cavities, resulting in deaths at temperature extremes.

The paper also details some inter and intraspecific interactions in nest boxes, and patterns of use in other cavity roosting species such as the Northern Flicker and European Starling. With this discussion comes supplementary video of some such encounters, and excellent inclusion to add further context.

WATCH THE VIDEOS (CLICK HERE)

READ THE PAPER (CLICK HERE) 

Published in Western Birds: First Record of Eastern Phoebe Breeding in Alaska

by Bryce W. Robinson

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My latest publication, and my first in the excellent regional journal Western Birds (Western Field Ornithologist’s), details the first documentation of successful breeding of Eastern Phoebe in Alaska. You can find the pdf on my Researchgate profile. It’s short and to the point, and worth a read for anyone interested in the birdlife of North America.

Last year, while working in Alaska with the US Fish and Wildlife Service’s Migratory Bird Program, I caught word of an Eastern Phoebe documented near Nome. I’m very familiar with Nome, since it is where I studied the Gyrfalcon for my master’s degree. I’ve birded the area heavily in the spring and summer months. There aren’t many Eastern Phoebe records for the state, so a bird showing up in Nome on the western coast is that much more exciting. I planned to be in Nome the following month to work with Red Knots, so I crossed my fingers that the bird would stick around long enough for me to see.

Surprisingly, a second Eastern Phoebe was documented soon after. Then came documentation of nest building, followed by nesting behavior and ultimately confirmed egg-laying and incubation. On my arrival at the start of July, I joined my friend Lucas DeCicco to see the pair on the outskirts of Nome. Since July is a time when the flow of birders ebbs in Nome, no one had checked on the nest for some time.

Sure enough, we found the birds feeding nestlings. After we had photographed and observed, Luke and I resolved to return regularly to document the success or failure of the pair.

In the end, the pair was successful. It was the first documented case of the species successfully breeding in Alaska, and on top of that in a location quite inhospitable and atypical of the species. The coast of Nome is not known for mild weather.

I told Luke that I thought it important to document this novel event in a publication, and he agreed. So we resolved to report the record, and asked for the help of those that originally found the first phoebe in June.

Thanks to Luke for his help with this seemingly simple publication. It wouldn’t be so clear, simple, and clean without him. Also, a big thanks to my co-authors who first found these birds – Aaron Bowman, Scott Hauser, John Wright. Thanks for the help with cleaning up the publication, and of course documenting the birds that led to this record.

White Wagtail Breeding in Teller, Alaska

by Bryce W. Robinson

 

Working again in Nome this summer, although for a relatively short time, provided me with the opportunity to attempt to see some of the birds of the region that I had missed in previous years. One such bird was the White Wagtail (Motacilla alba). Before traveling to Nome, my friend Luke had informed me that he had already seen the species in a lagoon near the Red Knot camp, so my chances were promising.

Red Knot work was in full swing when I reached Nome, which limited the chance to try for the wagtails. In the meantime came a report of a White Wagtail AND a Common Ringed Plover (Charadrius hiaticula) in Teller some 40 miles from our camp. On 5 July, a day of rain and weather, we took advantage of the inability to work with Knots and headed to Teller to try for both birds.

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An alarm calling adult White Wagtail (Motacilla alba) in Teller, Alaska.

When we reached Teller we began the search, more focused on the plover than the wagtail as the bird was a lifer for most in the group and the wagtail was not. After 20 minutes of fruitless plover searching Luke spotted our other target, a wagtail at the north end of the village. Luke and I both set out to photograph and film the bird and soon realized it was carrying food. Another adult appeared, also with food, and our minds tipped to the possibility that these birds bred in the area. Jim (head of the Red Knot project) watched the food carrying adult and followed it back to an electricity box on the side of a nearby building. The bird entered the utility box, and exited without the food. We quickly backed the truck up below the box to gain access and check for nestlings. Sure enough a grass nest sat in the corner of the box containing small nestlings.

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Electricity box containing a White Wagtail (Motacilla alba) nest. Teller, Alaska.

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White Wagtail (Motacilla alba) nest. Teller, Alaska.

After quickly documenting the nesting situation we left and let the adults return to provisioning the young. At the end of the day we left Teller with an excellent experience with White Wagtail, but unfortunately no Common Ringed Plover. Such is birding.

A few weeks later on 22 July, Luke and I returned to Teller on another poor weather day to check on the success of the brood. We soon found multiple juvenile wagtails chasing the adults, begging for food. Luke mentioned that White Wagtail had bred in Teller in years past, but I was left feeling like I had just struck oil – My first White Wagtails, breeding at that!

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Juvenile White Wagtail (Motacilla alba). Teller, Alaska.

The experienced left me excited. I’ve found that the best way to deal with the hangover excitement of a great birding experience is to illustrate, so after the initial sighting of the adults in early July I took advantage of the next day of weather and painted a White Wagtail on the inset of my Nome 2016 sketch journal.

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White Wagtail (Motacilla alba) in the inset of a 2016 field season sketch book for birds of the Seward Peninsula, Alaska. 

Seeing a bird species for the first time, and one that is quite uncommon in North America at that, is the best of birding. Especially if it feels like its been a long time coming. To see the bird and gain a first hand account of its breeding habits, well that is something else. It has a context, and context is what makes my experiences fruitful. I love life histories of birds, especially regarding breeding. I consider this experience to be the example of the what I seek when I step out the door aimed at observing birdlife.

July 2016 in Nome, Alaska had some magic, or something. But it seems that it was a continuation of a theme that started in early May. I bet that if you were to ask anyone that traveled to Nome, AK in the summer of 2016 they would agree. It was special summer, and I can’t wait to hear reports of what the fall brings in the region.