Tuesday, December 23, 2008

first-winter THAYER'S GULL @ Windsor Landfill

Julian Hough, James P. Smith and I spent a few hours this afternoon at the Windsor-Bloomfield Landfill. It turned out to be another successful trip.

At noon I picked out this bird as a candidate for a first-winter Thayer's, and Julian and I worked on it for a little while before losing sight of it. James arrived and we refound the bird around 2pm and continued to watch it until sometime around 3:15, when Julian and I left. James planned on staying a little while longer.

The identification of Thayer's Gull in the east is a controversial one, but I believe this to be a nice example of a first-winter Thayer's. For example, compare this bird to the "typical midwinter individuals" photographed in Howell & Dunn, page 265, images 36.10 and 36.11. As usual I would love to hear comments, either positive or negative.

I did not capture any flight shots, but in flight the bird showed a dark secondary bar, a solid dark tail band with mottling at the bases of the outermost retrices, and the "venetian blind" pattern of the outer primaries.

To view James P. Smith's images, check out his blog.

Here are a selection of images, none of which have been altered other than cropping and labeling.


Masked face, head more rounded than Herring Gull, tertials slightly darker than upperparts, primaries darker than tertials. The dark (but not black) primaries have neat and narrow pale fringes to their tips. The slim (but not tiny) dark bill has a hint of paleness coming into the base of the lower mandible.


From underneath the flight feathers of this bird looked like those of a white-winged gull. Note that the outermost primaries are just as silvery as the rest of the flight feathers...HEGU's outer primaries would be slightly darker from below.


Tertials are dark-centered with marbled tips. In this photo one can also see the brown tail band, which was probably captured much better in Julian and James' flight shots (they also captured the upperwing in flight).


All scapulars are juvenile feathers, which is good for Thayer's as they average a later molt than Iceland.






Thayer's Gull in foreground, Herring Gull directly behind it. A nice comparison of the difference in head/bill structure between the two.




Thayer's Gull facing away, giving another glance at the solid brown tail band. Note the first-winter Iceland Gull in the upper right.


adult Glaucous Gull...a real stunner that put on a bit of a show for us; my first ever adult Glauc (quite a rare age in Connecticut)

Also present on the day were that adult Glaucous and at least 5 "Kumlien's" Iceland Gulls (1+ adult, 4 first-winters).

This is turning out to be quite a winter for gulls at this location. For anyone looking to learn gulls (can be a daunting task), this is a great place to study them.

Merry Christmas!

- Nick

3 comments:

  1. Hi Nick,
    Great posts with id information on all these gulls. I really have picked up some great tips on gull id on your blog. Thanks!
    Merry Christmas!

    ReplyDelete
  2. Nick,

    This is a classic Thayer's. Small dove like head, slight bill, dark tail, checked tertials and obvious white crescents on the primaries. This bird is dark enough that it eliminates any possibility of an intermediate Iceland type. As a former Gull watcher at the old Manchester Dump back in 80s and early 90s, I would love to be back in CT now, but I get to see plenty of young Thayer's here in CA. Great find

    ReplyDelete
  3. Nick,

    Looks like a great Thayer's to me as well. I really must keep an eye on the gull flocks here on Long Island!

    ReplyDelete