Monday, January 14, 2008

Thayer's trio, Cape Ann, MA - 01/13

A return visit to Cape Ann with Scott Surner, mostly in pursuit of the Slaty-backed Gull, produced another exceptional gull show at Niles Pond, Eastern Point. Although the Slaty-backed didn't show up during our six hour vigil, we and our friends were stunned to have not one, not two but three Thayer's Gulls at close range towards the end of the afternoon! Later review of the images revealed that one of the birds had been well seen on January 5th and 10th, but two others, also first-cycle birds, appeared to be new. Erik Nielson who birded with us for some of the afternoon saw all three of these birds and was certain that a first-cycle Thayer's that he'd seen the previous day at Niles was not amongst them. Images of all three birds appear here.

First cycle Thayer's Gull - bird #1, discovered at around 14:10hrs.

First cycle Thayer's Gull - bird #1, with Kumlien's Gull in foreground.

First cycle Thayer's Gull - bird #1. Showing brown centers to tertials and black-brown primaries with neat pale fringes.

First cycle Thayer's Gull - bird #1. Nice shot of spread wings, courtesy of Scott Surner. Shows dark brown outer webs of outer primaries with paler inner webs creating two-tone effect. This bird did have a dark secondary bar which isn't shown that well in this shot.

First cycle Thayer's Gull - bird #1. Very easily lost amongst smithsonianus, especially if the the bird was partly obscured. The Thayer's is in the foreground, second from the left.

First cycle Thayer's Gull - bird #2, discovered at around 15:15hrs on the ice at very close range. Very subtle and delicate patterning to upperparts, but again showing solidly brown centered tertials and much darker brown primaries, neatly tipped and edged whitish. Beautiful bird.

First cycle Thayer's Gull - bird #2.

First cycle Thayer's Gull - bird #2, stretching wing. Direct comparison with first-cycle American Herring Gull. Slightly smaller, more delicately built than smithsonianus with more delicate (less coarse) patterning above and lighter tones to both tertial centers and primaries.

First cycle Thayer's Gull - bird #2. Not a great angle, but the darker secondary bar can be seen. The primaries appear to be the darkest part of the plumage, darker than the broad mid-brown tail band.

First cycle Thayer's Gulls - bird #2 in foreground and bird #3 at rear.

First cycle Thayer's Gulls - bird #2 in foreground and bird #3 at rear. The bird at the rear is almost certainly the same that Brian Kane and I initially discovered in Gloucester's Inner Harbor on January 5th, and I subsequently saw at Niles Pond on January 10th.

Another great (perhaps unprecedented) day with the Cape Ann gulls. We also think that something in the region of 40+ Kumlien's Gulls used Niles Pond during the course of the day.
Many thanks to Scott for driving us out there, and the use of one of his images here.

For web references, Jeff Poklen's stunning image set of Thayer's Gulls from California is really worth a visit. Check out the broad variation in first-cycle birds. All the images are worth viewing.


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