The bird below is a second winter (2CY), judging from the black leading edges to primaries 9 and 8. What is unusual about this bird is that its five outer primaries are white (P6-10) along with the associated greater coverts and some of the smaller coverts as well. Normally only P7 to P10 are white. I know that some of the more eastern Black-headed Gulls can show this feature, so I wondered whether this could be a sibiricus bird. Not very likely, perhaps, but the weather at the time was well below zero... Maybe white P6 is a normal variant in ridibundus - anyone know?
(See this thread at Gull Research for comment on this bird, which suggests this is within normal but as yet undocumented variation for ridibundus)
1 comment:
> Maybe white P6 is a normal variant in ridibundus - anyone know?
No. No idea. But it's another interesting one to look out for!
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