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Tag: raptor

Published in the Journal of Raptor Research: Defining Raptors and Birds of Prey

by Bryce W. Robinson

 

Raptor Cladogram

Figure 1 from McClure et al. 2019, ‘Defining raptors and birds of prey’ in the Journal of Raptor Research. Raptors, under our new definition, include all orders encompassed by the gray box in this figure. 

In the latest issue of the Journal of Raptor Research, colleagues and I, led by Chris McClure, published a commentary proposing a definition for the terms raptor and bird of prey. 

The definition is essentially all orders of core land birds (Telluraves) in which the majority of the members have maintained an ancestral raptorial condition. In other words, raptors or birds of prey belong to a group of birds that descended from an ancestor that had a raptorial lifestyle and morphology. The species that evolved from this common ancestor and maintained raptorial characteristics are thus considered raptors. This places the orders Accipitriformes, Cathartiformes, Falconiformes, and Strigiformes together as raptors, a grouping that is largely consistent with tradition. The big change is that this group also includes the order Cariamiformes, an order containing the two species of Seriemas from South America. This is the first time that Seriemas have been included as raptors (apart from a suggestion in Jarvis et al. 2014), but as we outline in the paper the natural history of the species along with its placement in the evolutionary grade cause it to fall under our current definition of raptor and bird of prey. So, welcome Seriemas to the Raptors!

As I stated above, the orders Accipitriformes, Cathartiformes, Falconiformes, and Strigiformes have all traditionally been considered raptors and birds of prey. But, there has also been considerable disagreement about the inclusion of some of these, such as Cathartiformes (New World vultures) and Strigiformes (owls). There has also long been discussion about the inclusion of shrikes (Lanidae) and ravens (Corvidae) because they either share some raptorial morphology and life history characteristics, or fulfill a similar ecological niche. This disagreement has caused many discussions in my life alone. I recall multiple discussions about whether or not Turkey Vultures are raptors, which stirred much of the conversation that led to my involvement in the publication of this paper.

Now, we don’t have to argue, Turkey Vultures are raptors. Since this definition is backed by much of the raptor research community, and is solidly outlined, defensible, and now published in the Journal of Raptor Research, I believe this new definition properly orients us to what is and is not a Raptor or Bird of Prey. We can now move forward and focus on the important work of conserving much of the members of this group.

Read “Defining raptors and birds of prey” open access here.

 

 

Raptors of North America – Northern Goshawk (Accipiter gentilis) Illustration

by Bryce W. Robinson

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I’m working to illustrate the raptors of North America. To help me out along the way, you can purchase limited editions prints of plates, like this image of the Northern Goshawk (Accipiter gentilis), in the shop.

A special thanks to HawkWatch International and Golden Eagle Audubon Society for their support of my work.

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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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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