A studio for bird study

Tag: sandpiper

Sharp-tailed Sandpiper (Calidris acuminata) on the Alaska Peninsula

by Bryce W. Robinson

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The Sharp-tailed Sandpiper (Calidris acuminata) breeds in eastern Siberia and winters in the south Pacific, but a large portion of the juvenile cohort pass through western Alaska on their first fall migration. While I was on the Alaska Peninsula waiting for Bar-tailed Godwits (Limosa lapponica) in September, I got to see a few late moving juvenile Sharp-tailed Sandpipers mixed in with massive Dunlin (Calidris alpina) flocks.

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At high tide each day our group would hide in the elymus grass and watch shorebirds come into the high rack line to roost. On one occasion, I noticed the opportunity to photograph a juvenile sharpie, so crept on my belly towards the roosted flock. Once I was close enough to take quality photos, I raised my camera. At the same time the flock took to the air and my chance seemed ruined. I thought it odd though, because the roosting Dunlin are usually tolerant if you are careful and move slowly. I looked around and saw a Bald Eagle passing overhead, which was certainly the reason for the panic. I cursed a bit and looked around to see when the flock might return to roost. As I scanned around, I noticed a lone bird still roosted in the rack line. It was the sharpie, which hadn’t pushed to the air with the Dunlin flock. It’s an interesting note, and something I’ve observed with the few Rock Sandpipers that were associating with the Dunlin flocks as well. On few occasions, the other species opted to stay put despite the flock erupting into flight.

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I’d love the opportunity to get to know Sharp-tailed Sandpipers better. Like other birds of the region, the juveniles represent one of the excellent species along the migratory route of the west coast of Alaska that make the place so unique and alluring.

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Rock Sandpiper Short

by Bryce W. Robinson

Rock Sandpiper – Calidris ptilocnemis. As seen through the ZEISS Diascope 65 T* FL

Rock Sandpiper – Calidris ptilocnemis, From Curiosity Stems Study

by Bryce W. Robinson

ROSA

Here in western Alaska I’ve been able to spend a bit of time pausing from a focus on Gyrfalcons to watch the Rock Sandpiper – Calidris ptilocnemis on its breeding grounds. My fascination with its appearance, behavior, and vocalizations caused me to look into what is known about their populations and distribution, a factor of bird biology that I’m growing evermore interested in studying. My investigation led me to understand that there occur three separate subspecific populations in Alaska, the nominate ptilocnemis of the Pribilofs, the tschuktschorum of the western mainland, and couesi of the Aleutian archipelago. As I am currently conducting research on the Seward Peninsula, I have been experiencing Calidris ptilocnemis tschuktschorum. 

After some further reading, I learned that the nominate ptilocnemis has the most northern wintering region of any North American shorebird. Remarkably, these birds spend their winters in the Cook Inlet of coastal Alaska. How they manage to find enough food and weather the extreme temperatures and conditions is above my current comprehension, but I was able to find some literature on the subject. Apparently, their is no physiological characteristic or attribute that separates ptilocnemis from other Rock Sandpiper subspecies that would give it the edge to winter so much farther north. The other Rocks could physiologically manage a winter in the north as well, but for whatever reason ptilocnemis is the only ssp. to do so. This seems like a peculiarity, and that is precisely why I am so fascinated by their distribution.

There are other Calidris species that are polytypic, and have separate wintering grounds for each subspecific population. Learning about such cases is extremely enlightening and begs for some contemplation on the matter. Perhaps a polytypic species such as the Rock Sandpiper, or the Red Knot will have an edge on anthropogenic induced changes affecting key migratory sites and their ability to survive the great journey. Perhaps the ability to buffer such disruptions is already built into their distribution at the species level. They are certainly better off than a monotypic species that stops over or winters wholly in a small and localized area. If the lower Pacific Coast of North America becomes a dead zone, then perhaps the subspecies couesi and tschuktschorum will be hard hit, but the nominate ptilocnemis may fair well and maintain a presence for the Rock Sandpiper in North America. As we attempt to be aware of our ever increasing impact, it sure would be nice to know that some birds will be able to wear the disruption, even if it is to a minor degree, so we can then put more energy into those more sensitive.

 

Referenced information:

Gill, Robert E., Pavel S. Tomkovich and Brian J. Mccaffery. 2002. Rock Sandpiper (Calidrisptilocnemis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:http://bna.birds.cornell.edu/bna/species/686

Ruthrauff, D. R., A. Dekinga, R.E. Gill, and T. Piersma. 2013. Identical Metabolic Rate and Thermal Conductance in Rock Sandpiper (Calidris ptilocnemis) Subspecies with Contrasting Nonbreeding Life Histories. The Auk 130 (1) pp. 60-68

Birding in South West Idaho

by Bryce W. Robinson

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It has been a while since I’ve posted to this blog, due mainly to the fact that some poor luck fell on me, and my laptop was stolen from my desk in my office while I was off teaching. Luckily, most of my photos and video were backed up, but it’s been rough not being able to share anything while I’ve searched for a solution. For the meantime, I’ve found a temporary fix in borrowing a computer. This has allowed me to look through some photos I’ve gathered while I was computer-less.

Anyway, the photo above was taken yesterday morning. I went for a day of birding with some new and talented Idaho birding friends to a large reservoir on the west end of the Treasure Valley. It was a great day with some good birds. We ventured to Deer Flats Reservoir in the early morning, making it to the mudflats just as the sun rose. The light was electric, and luckily we found some tolerant Least Sandpipers. I again found myself on my elbows and knees, shooting shorebirds, remembering my summer in the north.

I don’t know much about birding in Idaho, but I sure am learning. We found a juvenile American Golden-Plover, which is a great bird here. It was a lifer for one of the fellows in our group. That is always fun to be a part of, in my opinion, even if it is not you who gets to see something new.

Here are the ebird checklists for those interested in knowing what we found:

http://ebird.org/ebird/view/checklist?subID=S15553530

http://ebird.org/ebird/view/checklist?subID=S15553364

http://ebird.org/ebird/view/checklist?subID=S15553253

http://ebird.org/ebird/view/checklist?subID=S15553246

I really enjoy the new birding community I’ve found here in Idaho. Lots to learn as always, and hopefully now that I have a way to blog again, I’ll keep the posting regular.