Saturday, February 7, 2009

Thayer's like Gull, Barton Cove, - 02/04

'Thayer's like' Gull - first-cycle (left). This bird appears in the lower left/center of each of the following images.

This first-cycle gull caught my eye when scanning through the assembling gulls at Barton Cove, Gill. I'll say from the outset that conditions weren't great. The light was beginning to go and I found the bird late with its head tucked into its upperpart feathers, a posture which it retained for most of the observation. I found it whilst searching for a Nelson's Gull when all the gulls were flushed by a raptor a few minutes earlier. When I found this bird, I initially thought I'd relocated the Nelson's due to its rather 'milky-coffee' colored plumage, frosty fringes, and brownish (not black-brown) primaries. I became increasingly interested on seeing the head and bill shape, as well as the rather light-mid brown centers to the tertials. Close inspection with the scope revealed distinct neat whitish tips and fringes to the primaries which is admittedly difficult to see in these shots but can just be made out.

In flight over the cove, even in poor light, it looked very good for Thayer's, and I could follow the bird amongst c.800 other gulls due to the near translucent appearance of the underwing and especially the tail band which looked mid-brown, narrower and lighter than in American Herring Gull.

On Feb 6th, I relocated the Nelson's along with a Glaucous, 2 Kumlien's Iceland, and 2 Lesser Black-backed Gulls, but unfortunately had no sign of this bird. Looks like I might have to let this one go as a near miss!

As always, I'd be interested in receiving comments concerning the identification.



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