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4cy Caspian type

Posted: Mon Oct 14, 2013 6:53 pm
by little-W
Hi all,

I would like your thoughts on this 4th-calendar type bird, seen last week at the waste dump of Barneveld, The Netherlands.

It is showing a mix of Caspian and Herring/Yellow-legged features:

- Broad bill with well-marked gonydeal angle (Herring/Yellow-legged)
- Dark iris
- Head pattern reminiscent of Yellow-legged
- Gray tone as Caspian (too dark for Herring, too light for Yellow-legged/argentatus?)
- P10 with white type and small dark spots on both webs and P9 with small mirrors on inner web should rule out Yellow-legged
- P10 tongue invisible unfortunately
- P5 with black on both webs forming band, on outer web deeper than on inner
- No black on P4
- All white tail

Re: 4cy Caspian type

Posted: Sat Oct 19, 2013 3:26 pm
by adriaens
Hi Maarten,
before going into the hybrid/Caspian debate, I am wondering if this is not some kind of Herring Gull?
I see nothing that really excludes that option...

Re: 4cy Caspian type

Posted: Mon Oct 28, 2013 11:49 am
by little-W
Hi Peter,

No, I can't exclude a Herring either.
Other suggestions that I have received about this bird so far range from 'something funny from Poland' and Yellow-legged.

Re: 4cy Caspian type

Posted: Mon Oct 28, 2013 10:25 pm
by Theo Muusse
I am in the Peter camp.
There is a herring feeling on this....

Theo