ML534751971
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- Edad
- No especificado
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Detalles de la observación
33.89143° N, 117.10188° W At NE corner of pond G2 in the San Jac wildlife area. Associating with Least Sandpipers. Will post details later. Went there with Tony Metcalf’s group. Originally found by Charity Hagen in January with suggestion of stint from David Rankin and Tony Metcalf. I heard about the possible stint yesterday from Curtis Marantz and since I was in town briefly, I decided to head out there this morning. Arrived at 700 AM and drove with Tony Metcalf's SBVAS group to the G Ponds. We walked out along the north edge of the G pond, out to the NE corner of G2. Almost immediately upon arriving, we saw a few Least Sandpipers working the muddy shoreline. I spotted a pale gray Calidris off in the distance that looked very promising. Tony put the scope on the bird and it was clear that this was the stint. For about 2 hours, we watched this bird move back and forth along the shoreline. It loosely associated with the Least Sandpipers flock of about 10-15 birds, but sometimes it would forage on its own. There were no other Calidris species, making it relatively easy to pick out the whitish stint from a distance. Other shorebirds included a couple Long-billed Dowitchers. Every once in a while, the flock of Leasts (and stint) would fly up, but they would quickly return. They did not seem to be overly bothered by our group of 20 birders. The sandpiper stood out in having a white belly, a whitish chest with some pale gray smudges on the sides of and across the chest, and cold gray upperparts, in stark contrast with the Leasts with brown uppersides and brown chest. Structurally, the sandpiper resembled Western/Semipalmated. It had long primaries that extended beyond the tail tip. Primary tips even appeared to cross in some angles. The bird had a distinct profile: a humped back and an extremely attenuated rear due to the long wings. There was a distinct dip at the base of its back as one follows the bird's profile toward to the tail. This back profile contrasted with the shorter-tailed and straighter back profile of Least (Semipalmated Sand also has straight back profile; Western has a slightly attenuated rear, but nothing as extreme as this bird). The bill was thin and longer than Least Sandpiper, within the range of male Western Sandpiper or the range of female Semipalmated Sandpiper based on my experience. Bill shape was intriguing. Culmen was straight, but lower mandible curved at its base, something I have not seen in Western. Legs were all black and significantly longer than Least. While the Least looked like they were "crawling" close to the ground (and usually foraging on the mud or very shallow water), the bird in question stood taller, often walking in slightly deeper water. Legs were not held bent as much as Least. When the sandpiper was on the mud, it would often run around frenetically. Tibia are thin. Upper tibia thinner than lower tibia. After inspecting a thousand photos, I finally found one in which the feet are spread apart. There is no webbing between any of the toes. We were not able to discern this in the field though. See one of the attached photos. Plumage. The bird was overall gray above, slightly darker than what I am used to on winter Westerns. In particular, the covert feathers had dark feather centers, another feature I don't see on Westerns. Most of the covert feathers appear to be fresh. The bird had a grayish crown and check and a whitish supercilium. However, the supercilium appeared to be split when seen from certain angles. Chin was white, and because of the slightly gray wash to sides of chest (with fine streaks) and sparse gray across the chest, this gave the impression of a slightly contrasting whitish chin-pale gray chest band, something one typically only sees for Semipalmated, Red-necked and Little Stint, not Western. Tertials appear to be worn based on inspection of photos, contrasting with the fresh primaries. My guess is that this is a first-year bird, with some old juvenile tertials retained. At no point did I hear it call even though I was listening very carefully. Based on the photos of the spread toes, this bird is undoubtedly a stint. Kudos to Charity Hagen for finding it and others for bring the bird to everyone's attention. I think Rufous-necked Stint can be ruled out based on bill structure and length as well as leg length. Rufous-necked has shorter legs and tends to be closer to the ground, whereas this bird looked like it was standing tall. Rufous-necked's bill base tends to be thicker and overall bill is shorter and more conical, without the straight culment, pointing tip and curved lower mandible base of Little. Dark centers on covert feathers I think points to Little. Finally, Rufous-necked stint would probably have more extensive gray across chest.
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