4cy Caspian type

[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

[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...

[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.

[Theo Muusse]

I am in the Peter camp.
There is a herring feeling on this....

Theo