Friday, 28 January 2011

Hate gulls? Look away now

Adult Caspian Gull at Rainham today, with argenteus Herring, graellsii Lesser Black-backed, Black-headed and Common Gulls. Note the head and bill profile, small dark eye, dull yellowish legs and general posture/jizz.
Wing-tip detail of the same bird as it flew. P10 has the classic extensively white tip shown by most adult Caspians, and P9 has a large white mirror across both webs. The black subterminal band on P5 is complete.
Bitter is not the word. My car told me it was between 1 and 2 degrees C on the way to Rainham this morning, but after standing in the open on the landfill in a stiff north-easterly for five hours, barely without moving, I can vouch that the wind chill factor made it considerably lower than freezing. So please humour me when I share this latest batch of gull shots - don't let me think I've lost several fingers and toes to frostbite in vain. Enough said - the pictures and captions can do the talking.

With its mustard-yellow bare-part coloration this adult gull suggests michahellis, albeit with a white-tipped P10 (rare in that species). Martin Garner and I have corresponded about it, and he has also consulted Chris Gibbins, who has looked at eastern michahellis a lot recently; they are happy this is a Caspian Gull, with the bright bare parts and size making it a male. Importantly, note the iris is pale - not dark, as wrongly claimed elsewhere - and the bill rather deep (compare with the other adult Caspian Gull above). A trap to watch out for in future ...

 The same bird as above - note the rather thick-necked jizz and heavy-looking bill of this individual.

 A crop of the same image, enlarged to show the pale iris and mustard-yellow, rather deep bill.
 Open wing-tip on the same bird. Note that black markings just extend to P4.
A sub-adult michahellis Yellow-legged Gull, with dark bill markings and black on the primary coverts.
First-winter Caspian Gull (centre) with first-winter Herring Gull (behind). A useful comparison shot: note the Caspian's whiter underparts, more solidly brown wing coverts, different scapular pattern, 'shawl' of hindneck streaking and bill and eye. This is a Polish-ringed bird, 65P6, ringed in May 2010 in Upper Silesia.

The same first-winter Caspian, this time showing the upperwing and underwing patterns, and tail.
One for the road: a monster adult or near-adult argentatus Herring Gull. This taxon is common at Rainham.
Below: click the 'play' button for a movie clip of today's adult Mediterranean Gull.

2 comments:

  1. Excellent photos and a majorly impressive argentatus.

    ReplyDelete
  2. I am really enjoying these gull photos, very imformative.

    ReplyDelete

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