Tuesday, 5 February 2013

Russian Common Gull (Larus canus heinei), 2cy, 16.1.2013, Svanemøllebugten, Copenhagen

It is the upper left individual. Note that it is taller, but also stronger and heavier than the average canus in direct comparison. Note the heavy breast and beer belly...

On January 16, 2013 I photographed this large heinei Common Gull in Copenhagen. Together with Kjeld Tommy Pedersen I was out feeding gulls and it was immediately striking mostly due to its long wings, large size and heavy structure compared to the nearby canus. Due to its long legs, pushed up breast, slender and elongated structure and long bill, there was almost a cachinnans jizz to it. It was obviously much taller and structurally different from all the canus.

Luckily, Kjeld caught and ringed the same bird a few days later on January 22, 2013 which allowed for the needed measures to confirm the identification. It had a total head length of 100.6 mm and the folded wing was 395 mm – thus clearly a heinei on wing length (max wing in canus 390mm). According to Kjeld one should actually add 7-10 mm to the wing measure because it is a 2cy individual and they grow even longer with age. It was really a long winged and large individual.

It was ringed with metal AC 5558 and yellow colour ring with the inscription K9J.

It is the left of the two individuals seen from behind. Note the thicker and longer legs.

Note the densly dark-patterned hindneck, creating solid dark necklace.

Retarded moult in February with massive presence of juvenile feathers in upperparts is a classic heinei feature; however, it can also occure in late breeding canus from northern populations.

The bill is heavier and more parallel-edged relative to canus in direct comparison.

It was a large bird...

Note the relatively broad tail band and how the black on especially the outer feathers creates bayonets. On some Common Gulls wintering in Japan, the black tail band is wide enough to reach the edge of the uppertail coverts. Photo: Kjeld Tommy Pedersen.

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