Caspian? or hybrid in Denmark

[Kent Olsen]

The Caspian with some argentatus-jizz and slight head-streaking has supposedly returned to Aarhus Harbour for its at least fourth winter. Please have a look:

http://gulldk.blogspot.com/2010/12/casp ... -2_04.html

Some of you have already commented last winter viewtopic.php?f=13&t=137 but now the pictures have become better which might change your thoughts.

Cheers

Kent

[JanJ]

Well Kent,
same bird - much better pic! However, as much as it has a set of good Caspian features (mentioned before) I´m still not sure what to allow my self to decide, pure bird or not. Everyone is scared (shitless ) to identify atypical birds, quite understandible! However, it varies from bird to bird, you simply have to have at least a set of 89,5 % ot more (?) of so called typical Caspian features to be able to decide, does it look like a Caspian - it probably is one, otherwise not. Slightly different jizz in various pic, some showing almost perfect jizz, highbreast, flatish back etc. I find the primary projection quite acceptable. Another, perhaps minor detail, is the oval impression of the eye, which steems from the broadness of the orbital ring , both in front of and back of the eye, in a michahellis fashion.
(I´m not suggesting michahellis!)

http://gneubauer.republika.pl/CachsAndHybrids.html

Cheers Kent and some good pic.

Jan

[Kent Olsen]

Hi Jan,

Great, that you would share a comment. I fully accept that due to the change in appearance between the different photos nobody feels comfortable with a final ID. Nevertheless it’s an interesting gull which forced me to follow it for a long time in order to take documentation for all the different characters; that was great fun.

Great link with wing-tip pattern from Poland, very informative.

Cheers

Kent

[Kent Olsen]

This is just an update. The gull has now returned for its fifth winter in a row

http://gulldk.blogspot.com/2011/12/poss ... -gull.html

Personally, I find a cachinnans x argentatus-hybrid a possible explanation based on field observations and especially characters seen in last year’s photos. However, as previously suggested a safe ID may not be recommended...

Cheers,

Kent

[adriaens]

The latest issue of British Birds (December 2011) includes a very thorough paper on identification of Caspian Gull and hybrids, by Chris Gibbins, Greg Neubauer and Brian Small.
It outlines a set of criteria for acceptance of a 'good' Caspian Gull outside the normal range.
Get it!

[Cristian Mihai]

Yep, the paper is really interesting.