Sunday 22 December 2013

Caspian Gulls

December is supposed to be a good month for Caspian Gulls, but they have been noticeable by their absense at Shawell. That all changed this weekend when I managed to find four, although one of them may not have come from pure stock. It was a 3rd-winter, but there is no real criteria yet available to separate birds of this age that look good but have just a couple niggling issues. This bird had amber coloured eyes rather than dark brown and compared to the other three it was a little shorter winged. Neither of these issues rule it out from being a pure Caspian Gull though.

The 1st-winter was a cracker - these really have to be seen to appreciate how smart looking they are - flying rats they are not! The photo below demonstrates the four colour scheme that makes them look so smart.

First-winter Caspian Gull

The first one I spotted was an adult. This one was very long winged and was most likely a male.

Adult Caspian Gull
The first two images are video grabs because they were distant, but it shows you can still get reasonable images.

I appear to be seeing two types of Caspian Gull, the text book elegant, small headed and long winged version and other more robust, shorter winged and less obviously small headed ones. My recent review resulted in me rejecting one that I now consider a Herring Gull x Caspian Gull, but others still meet the standard for Caspian Gull. Chris Gibbins has pictures on his blog of Caspian Gulls from the Ukraine that appear larger headed and shorter winged. Other images of gulls he photographed further to the east look more elegant. Whether it is a geographical variation or is there some Herring Gull genes in these western birds I'm not sure. One thing I do know is that Caspian Gulls are fully absorbing. 

The third-winter below is a striking individual especially as it stood between a pack of scruffy looking Herring Gulls. Its bill colour is good for Caspian Gull, as are its long legs and its plumage. The white mirror on P10 at this age is also a good feature. However, its eyes are quite pale, its head and bill shape are wrong and its wings are shorter than the other three Caspain Gulls I saw this weekend. This one is a Herring x Caspian hybrid as far as I can determine

Third-winter Hybrid Caspian x Herring Gull?
I saw another third-winter and that one was a classic. It flew off before I could photograph it, but I did get chance to share it with a couple of budding gull enthusiasts. 

Comments are welcomed especially on the third-winter in the photo above.

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