A studio for bird study

Tag: gull

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

A Highlight of Birding- Breeding Sabine’s Gulls

by Bryce W. Robinson

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I can write a book about how many birding highlights I had this past summer on Alaska’s north slope. It seemed every day I had a memorable experience that will last a lifetime.

I’ve mentioned before that Richard Crossley came to Prudhoe Bay on my last week of work in the region. I agreed to guide him around the oil fields for a day and show him where I had seen particular species. He, of course, had an agenda, and I was tasked to help him out.

We had a hell of a day. I think we started around 8 in the morning, and by midnight, I was still wandering around the tundra photographing birds. He was very keen on finding the Sabine’s Gulls, a bird of which I had seen little. Still, I had a reliable spot that would likely turn up a few gulls, in the least. Just after midnight, we headed that way.

We stopped near the spot I planned to check, only to photograph a small group of Semipalmated and Pectoral Sandpipers. While Richard took photos, I scanned about. I then saw a single Sabine’s some yards away. I alerted Richard. After scanning about a bit, we found a dozen more.

Excitedly we approached the group of gulls and began photographing. The gulls would lift off, and take turns harassing us. Such behavior is typical of breeding birds, defending their young. I took advantage of their tenacity and let my shutter fly. After gathering more photos than necessary, I began the search for the young. Soon enough I found a single bird across a pond, sitting with an adult. It was nothing more than a single ball of grey fluff. So adorable, and so vulnerable.

Our intrusion lasted only a moment. We recognized the stress we were causing the birds, and left. It couldn’t have been better; finding Sabine’s, which I’d barely seen, and having the opportunity to see both adult and young at such close proximity. The experience will stick with me for my lifetime.

The tragedy comes with the benefits of digital photography. Through some glitch, I lost nearly all photos from that evening. Luckily, I have one. It is a photo in the striking midnight sun of the arctic, of a bird I will never forget, and hope to see again, somewhere on the open arctic tundra.

 

Lost Gulls in Prudhoe Bay, Alaska

by Bryce W. Robinson

 

Great Black-backed Gull- Larus marinus

Great Black-backed Gull- Larus marinus

If you’ve started to read, then I’m impressed. Gulls in the title is probably a big turn off for most birders. But in all purity, this is what birders love. VAGRANTS. 

Still, Gulls? It is my opinion that the average birder is bored when it comes to gulls. Bored not at the lack of challenge, for there certainly is a challenge, but bored at the birds general appearance and habits. These are simply assumptions on my part. I actually don’t know the reason for the lack of enthusiasm, but I bet the reasons for low numbers of “laruphiles”, or gull lovers, are numerous. Still, it is undeniable that it is widely understood that gulls are not the most exciting subjects when it comes to birding. I on the other hand, have felt an itch for paying attention to this highly successful bird group.

There are only two gulls that breed on the north slope of Alaska, being the Glaucous Gull, and the Sabine’s Gull. Both birds are rather distinctive. The Glaucous Gull differs from other large gulls by having a notably pale back, with entirely pure white remiges. This look is distinctive, even at a distance, allowing any oddballs to be easily recognizable.

The oil fields at Prudhoe Bay house a large number of people. With people comes trash, so it is no surprise that the oil fields have a dump. Dumps are gull magnets, and the dump at Prudhoe Bay is no different. Knowing that anything is possible in birding, I formed the habit of scanning the hundreds of gulls that hang around the dump from day to day. The habit finally paid off two weeks ago when I noticed a dark backed gull amongst the pale Glaucous Gulls.

I hurriedly snapped photos and analyzed the bird. To me, it resembled a Western Gull, but some aspects were a bit off. I also noticed that the bird was banded. Very exciting, given the ability to read the band. Reading bands is a complicated business, and as the gull was in an area that I was unable to enter, I couldn’t get close enough for a better photo, or a way to read the band myself. I wish I had explored my options further. This was the only time I saw the gull. So, no band number. 

I’m just learning the gull dilemma. It is a challenge. There is a lot to learn, and the differences between many species are slight. With this vagrant dark backed gull, I had to get some help. I emailed a friend in high places, and he soon got back to me with a consensus, along with the opinions of other authorities. The result was GREAT BLACK-BACKED GULL. A life bird for me, and a bird I hadn’t even considered. The back just didn’t seem dark enough. Still, after taking into consideration their input and analysis, I agreed. What a bird, so far from home.

In the following days I made my rounds by the dump, in hopes of finding the gull again to catch the band number. Last week, I thought I found the gull again, but actually, I had found something more exciting, a second dark backed gull. Immediatly I caught that this gull had no retained immature remiges, and had yellow legs. I knew the bird, even though it was another life bird; LESSER BLACK-BACKED GULL!

 

Lesser Black-backed Gull- Larus fuscus

Lesser Black-backed Gull- Larus fuscus

Lesser Black-backed Gull- Larus fuscus

Lesser Black-backed Gull- Larus fuscus

Sometimes birding is a game of curve balls. I never knew I could get so excited over gulls, but it spoke true to one of the reasons I am a birder. I love to find birds far from home, on crazy journeys themselves. I love to wonder why, and what they’ve experienced, and simply recognize that they are here, and how strange or miraculous that is.

Birders find vagrants everyday, some, much more exciting than these gulls that passed through Prudhoe bay. Nonetheless, the gulls helped me remember; This is birding, to notice something spectacular, that is so often overlooked.

Lesser Black-backed Gull- Larus fuscus

Lesser Black-backed Gull- Larus fuscus

 

 

 

 

 

Gluttony and the Great Blue Heron

by Bryce W. Robinson

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The other day I observed a Great Blue Heron- Ardea herodias, that had caught a fish seemingly too large to handle. The above image is directly after the bird had speared the fish, and was working on a way to get the meal down its throat. Yes, I did say spear. Before this instance, I was under the impression that herons never speared their prey, rather they stabbed at the prey only to grasp it in its bill. This bird speared the fish, effectively killing it, then retrieved it from the water. I believe that if the bird had not done so, the large fish would have been too strong as it struggled to escape the herons clasping bill.

I also was taken aback at the size comparison this photo illustrates between the Herring Gull- Larus argentatus, and the Great Blue Heron. Heron’s seem like such large birds when standing alone. Anyway, I took a sequence of photos of the heron struggling the fish down its throat. The sequence is as follows:

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IMG_2815You can see in the last photo where the fish still sits in the birds body. This will undoubtedly take a while to digest. I was impressed in the least. I absolutely love seeing predators eat, and the heron is one bird that always delights. I once came upon a photo of a Great Blue Heron that had killed and was holding in its bill a Least Bittern, about to consume the close relative. How bizarre.

Anyway, I felt lucky to see this instance, even luckier to capture it on film.