Rare Bird Accounts
Thayer's Gull (Larus thayeri)
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Rare Bird Accounts Thayer's Gull (Larus thayeri) |
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11/24/04 |
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Thayer's Gull (Larus thayeri) These pictures were taken on 11/20/2004 at West Point Dam, Troup County, Georgia by Bob Zaremba. This gull is accidental in Georgia. There have been three reports within a short period of time at Jekyll Island in January 1999. None of these reports were accepted by the GOS Records Committee. If accepted, this will be the first documented record for the state. Michael and Eric Beohm originally found this bird on November 12 at the same location but it had left the area and was not seen again until the 19th. The bird was actively feeding below the dam area most of the day and has remained in the area for several days now. This bird was extensively photographed by myself, Pierre Howard, Earl Horn, Jim Flynn, Giff Beaton, Michael Beohm and probably many others. Jim Flynn has placed a much better species account on the GOS website at http://www.gos.org/sightings/thgu.html with images from the other photographers mentioned above. The identification of this species is very tricky due to the general variability of gulls and it's similarity to the "Kumlien's" race of Iceland Gull. There are several very good references that you can read that help us to understand the differences and correctly identify this species. I found the following very helpful; Kenn Kaufman - Advanced Birding, Peterson Field Guides Series Kevin J. Zimmer - Birding in the American West, A Handbook P.J. Grant - Gulls, a guide to identification The bird found at West Point Lake below the dam shows very strong characteristics of a 1st winter Thayer's Gull. In the series of images below, several of the field marks that lead us to this conclusion are attempted to be captured. Starting with overall body size, the last image shows the THGU in a group of RBGU and you can easily notice the larger size compared to the RBGU. The head and bill shape look good for ICGU/THGU, smaller than a HEGU and relatively small head size. The culmen is some what rounded as compared to HEGU, and the bill is shorter than in HEGU and apprears entirely dark. ICGU could have an entirely dark bill as well (Kulmien's). The best field marks on this bird, IMHO,are the wingtips and tail. The tail shows the dark brown band of the tail feathers contrasting with the lighter rump and uppertail coverts. ICGU would not likely have such contrasting markings. You can also see in the images below the lighter primary and secondary feathers on the inside of the web. This gives the bird a "silvery" underwing pattern when viewed from below, visible in some of the images below. The color of the feathers were at most a dark brown, never approaching the black in a HEGU. The following set of images were taken with a Nikon D100 attached to a Swarovski Spotting Scope at about a distance of 100yards, the sky conditions were overcast and there was little light. Click on the thumbnail to enlarge the photograph.
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Birding Kennesaw Mountain Georgia Birding Trip Reports This site was last updated 11/24/04 |
