Wednesday, 11 August 2010

Caspian Gull (Larus cachinnans), 4cy, 7.8.2010, Balka, Bornholm

This 3rd summer Caspian Gull has relative long legs with longer tibia compared to argentatus. The eye colour is relative dark with a slight green peppering in the iris – peppering most easily seen when light hits the eye directly - and when seen at some distance it stands out as being all dark in contrast to argentatus. There is a thin red orbital ring seen at close range. The bill is relative long and without pronounced gonys angle. The bare part colour in the opened bill is spot on for cachinnans being orangey-yellow at the base of the mandibles where the skin colour in michahellis is typical blood red and light pink in argentatus.

It has a good cachinnans jizz with high push up breast, flat belly slightly dropped behind legs and long elongated slim rear. P5 has been renewed and has a broad black band. P9 has only small mirror and p10 has the white mirror separated from the white apical which is spot on for a near-adult chachinnans.

The primary pattern on p9 and p10, the dark pattern on primary coverts, the partly retained dark tail band and the rather pale bill colour all indicate that the gull is a 3rd summer individual.

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