Tuesday, January 15, 2008

Tricky Kumlien's Gull? - 01/13

Back to the Niles Pond gulls at Cape Ann, I've been receiving quite a few emails about another dark gull that was present at the same time as the three first-cycle Thayer's on January 13th. Initially, this one also gave a Thayer's-like impression and was clearly a very interesting bird that I looked at in some detail. While at times being close to Thayer's in appearance, I thought it too uniform in its overall brown tones, especially when the upperwing was seen well which actually showed almost no contrast at all. At rest, the brown plumage varied enormously with the quality of light with the first shot in this sequence being taken in dull overcast conditions. The head and bill shape also looked a little odd for Kumlien's Gull being closer to my impression of Thayer's. I'm not really sure where to place this bird. It may just be a dark Kumlien's Gull, or possibly a Kumlien's x Thayer's hybrid, or perhaps a bird best left unidentified altogether!


First-cycle Kumlien's or perhaps unidentified gull with Kumlien's Gull at rear. The bird looks especially dark in this image which was taken in dull overcast conditions.


First-cycle Thayer's Gull for comparison taken at around the same time under similar conditions. This bird shows much darker primaries, and short, bright pink legs.


First-cycle Kumlien's or perhaps unidentified gull. Very uniform upperwing. Only a hint of a secondary bar and no obvious darkening towards the outer primaries.


First-cycle Thayer's Gull for comparison. Show a noticeable secondary bar, dark brown outer primaries and a dark brown tail band. Overall impression suggests small, pale American Herring Gull.


First-cycle Kumlien's or perhaps unidentified gull with first-cycle American Herring Gull.


First-cycle Kumlien's or perhaps unidentified gull with Kumlien's Gull at rear. In this shot the primaries and tail band look significantly darker than the upperparts which contradicts the overall field impression which was of a more uniform bird.


First-cycle Kumlien's or perhaps unidentified gull. Taken in full sunlight in late afternoon. Again the primaries look dark in this image giving a Thayer's-like impression.




JPS.

1 comment:

Curt Powell said...

I've been wrestling with a very similar bird here in Michigan. I think the solid tertials point strongly to some Thayer's in the mix. Scaps etc to Kumlien's. I'm convinced it's a 'hybrid' or 'intergrade' or whatever you want to call it.

Here's a link if you're interested: https://www.flickr.com/photos/12965973@N06/23653466313/in/album-72157661033732203/

Curt