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October 8, 2019

Published in Marine Ornithology: Potential Northward Expansion of the Breeding Range of Red-legged Kittiwake Rissa brevirostris

by Bryce W. Robinson

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Black-legged Kittiwake (Rissa tridactyla; left) and Red-legged Kittiwake (Rissa brevirostris; right).

In a new paper published in Marine Ornithology, we report on an important result from the 2018 expedition to St. Matthew Island – documentation of previously unrecorded breeding activities for a Beringean endemic, the Red-legged Kittiwake (Rissa brevirostris). Our trip to St. Matthew was focused on Mckay’s Bunting (Plectrophenax hyperboreus) and Pribilof Rock Sandpiper (Calidris ptilocnemis ptilocnemis), where we both censused the populations of each and conducted a fine scale nesting study. While conducting this work, we opportunistically catalogued species presence and abundance, which led to the discovery of a large number of Red-legged Kittiwake occupying large cliffs on the northwest side of the island.

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Red-legged Kittiwake sitting on a nest (center) amidst Black-legged Kittiwake. This is one of ~50 individuals present at location B mentioned in the article.

Our paper in Marine Ornithology details what we found and where we found it, and also discusses the status of the species in the region. We discuss behaviors that we observed that indicated the birds likely attempted to breed on the island in 2018, although we were unable to confirm eggs or nestlings before we left in early July. Regardless, our observations of a few hundred Red-legged Kittiwake on St. Matthew is at least notable because it differs from past records that list only a handful of records of single individuals seen in waters near the island. Both the numbers and behaviors we observed indicate that the species has shifted its breeding range northward to include St. Matthew Island. Such a large latitudinal shift (~400 km) at a time of substantial change in the Bering Sea raises many questions, especially considering the status of populations at the core of the species breeding distribution, the Pribilof Islands.

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Figure 1. from the published report in Marine Ornithology 47(2). I was able to include a Red-legged Kitiwake illustration to elegantly communicate the distribution and relative size of Red-legged Kittiwake colonies, including the newly discovered colony on St. Matthew Island.

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Figures 2 and 3 from the report in Marine Ornithology 47(2). These figures describe the locations where birds were found, and their assortment on the cliffs relative to Black-legged Kittiwake.

As distributions of important food resources for seabirds shift, caused by aberrations in factors such as sea temperature, we expect to see distributions of seabirds that depend on these resources to shift as well (in the best case scenario). Currently, there seems to be ongoing massive starvation and die-off events of many seabirds in this region that are likely the result of an inability to respond to these changes in prey distributions. A northward shift in breeding distribution is promising for a Beringean Endemic, because it shows some plasticity in response to changes in resources. However,  we understand aspects of the Red-legged Kittiwake diet that partly explain why it holds a restricted range. Although a relatively small number of these birds have moved north to breed, characteristics of the habitat at and around St. Matthew Island may limit their success to produce enough offspring to maintain population stability. The story is ongoing.

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This shift in Red-legged Kittiwake distribution presents an opportunity to study species responses to climate change as they are occurring. Such study will not only further enlighten us on Red-legged Kittiwake life history strategies, but also on how species may or may not adapt to rapid fluctuations in food resources and climate caused by global anthropogenic activities. We need to stay focused on this region and these species, because they are telling us an important story.

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*Because of our observations in 2018, in summer 2019 (late July-August) USFWS returned to St. Matthew Island to conduct a comprehensive seabird survey of cliff nesting habitat and check for nesting Red-legged Kittiwake. They observed similar numbers at the same locations as our observations in 2018, and confirmed both eggs and nestlings. These observations confirm that the Red-legged Kittiwake now breeds on St. Matthew Island (at least in some years), and extends the breeding distribution for the species northward by nearly 400 km. 

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eBird checklists that document the 2018 Red-legged Kittiwake observations:

https://ebird.org/view/checklist/S47170141

https://ebird.org/view/checklist/S47199741

https://ebird.org/view/checklist/S47170187

https://ebird.org/view/checklist/S47170740

https://ebird.org/view/checklist/S47170322

https://ebird.org/view/checklist/S47170354

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October 11, 2018

Just Published in Marine Ornithology: Unusual Foraging Observations Associated with Seabird Die-offs in Alaska

by Bryce W. Robinson

 

Above is a short video that I produced to supplement a paper I, along with colleagues at US Fish and Wildlife Service and USGS, just published in the journal Marine Ornithology. The video shows behaviors that we describe in the paper, and will hopefully help the reader visualize what we experienced ourselves.

The Bering Sea region is changing in many ways, but among the most sobering are the mass die-off events that are impacting the regions birdlife. These die-offs continue into this year. Since we put together this publication of the observations that I and colleagues made in 2016 and 2017, the trend has continued and is likely to continue into the future. Furthermore, on my most recent trip to the region I documented further evidence of the ongoing change that is occurring across the bering sea ecosystem. There is and will continue to be more to report.

Some of the change, such as the evidence of starving and ill affected storm-petrels that are the subject of our publication, is sobering and concerning. It hits hard on the hearts of those of us who so passionately pay attention to bird life across the globe. We care deeply about the well being of these creatures that fascinate us so much.

Some of the change, such as some of my most recent observations in the region, are exciting and stoke curiosity, as the birdlife of the region responds to the impacts of ecosystem disruption.

Ultimately, there will be winners and losers as life navigates anthropogenic driven change throughout the world. Mass die-off events will become the norm for some species, until their populations can no longer sustain such losses and they are eventually lost to our world. Others will adapt in ways we cannot yet imagine. Such adaptations will undoubtedly open our minds to processes and function in ecosystems that we are yet to understand.

Yes, climate change is a problem. It is a problem that still is not unanimously recognized. It will change our world, our way of life, and probably not for the better. But, as we experience the change, we can document what is happening for the future inhabitants of our perturbed ecosystems. We can make record of the oddities, the aberrations, so that we leave a paper trail of first observations that will help us understand when things started, and how they developed. Hopefully, as these records build the evidence of change will become insurmountable to the point that the overwhelming majority of our society cannot and will not deny that the world is impacted by our daily choices and we ourselves need to change. And when we do, hopefully it will not be too late.

This is why I want to publish notes such as this, to make a record that will add to the evidence of an increasingly disrupted world. More to come…

You can find the paper detailing our observations of odd foraging behaviors here:

Click to access 46_2_149-153.pdf

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Video | October 30, 2017

Orange-breasted Falcon Plucking Prey

by Bryce W. Robinson

 

For the Orange-breasted Falcon whose diet consists primarily of avian prey, to eat requires a great deal of work. First, the birds must capture a food item. They specialize in above canopy surprise and pursuit capture, a technique that blends a bit of skill and luck. When the two align and the bird finally captures a meal, they then must prepare it. Falcons prefer to ingest little amounts of feather from their prey items, and thus need to efficiently remove the extraneous feathers to access the muscle. To remove these feathers, they pluck their prey nearly clean. Plucking can be beautiful, as I found with the Orange-breasted Falcon in the video above as it prepared a Great-tailed Grackle. Perched on a limb high overlooking a deep river valley, the bird plucks. The observer can easily recognize the bird’s technique of rip and flick, as it efficiently carries out its daily ritual and feathers calmly drift away in the hot Central American air.

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April 30, 2017

Sulphur-rumped Flycatcher (Myiobius sulphureipygius) Foraging in the Dark Understory of Southern Belize

by Bryce W. Robinson

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I’ve been in Central America for nearly two months, and I haven’t had the time or energy to post any stories, images, or illustrations from my experience thus far. There are of course many stories to tell.

Flycatcher (Family: Tyrannidae) diversity in Central America is very high. Getting to know this diversity has been an excellent challenge. I’ve had a lot of luck seeing most species that I might encounter in Belize, and among my favorite have been the small and endearing flycatchers of the rainforest, such as the Sulphur-rumped Flycatcher (Myiobius sulphureipygius).

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I’ve seen the bird only a few times. It sits low in the understory of the rainforest, near relatively open areas and perch hunts for insects. Its large eyes are obviously engineered to spot prey, and it tactfully watches and waits until it sees an opportunity. This can be for a minute or more.

These birds don’t seem to mind my close proximity when I’m watching and photographing, and seem only focused on its task of procuring food.

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Contrasting this seemingly patient and calculated technique with another small flycatcher, the Ruddy-tailed Flycatcher (Terenotriccus erythrurus) has been enlightening. From what I have observed, these birds are constantly making attempts at captures, and hardly sit still for more than a few seconds. It’s difficult to tell if these many attempts are all successful, because the insects it is after are much too small to observe at any distant.

Hopefully I’ll be able to capture both foraging techniques on video. There’s always another way to describe the behavior, whether it be writing, illustration, or video. I’d like to blend all three for these birds.

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