Tuesday 19 January 2010

Some examples of second winter Vega Gulls (Choshi, Japan)

I have loaded these pictures up to contribute to a small discussion on Surfbirds Forums (Advanced ID Questions and Answers) regarding the ageing of large gulls. The discussion focussed on the bird above, which in my opinion is a second winter. The same individual is shown below with its wings open (though under different light conditions). For comparison, examples of other second winter individuals follow; they are not the best photos, but I thought they might help the discussion (which related to the primary and secondary patterns of 2w gulls).

Two birds (above and below) with narrow but distinct white trailing edges to secondaries

A bird with hardly any sign of a pale trailing edge to secs.

And what about this one? It appears to have three different patterns in the secondaries. It is difficult to know for sure, but the different patterns may reflect different generation feathers. The white ones may be third generation, which suggests a moult rather different to Herring Gull. However, I don't want to overinterpret one image of one bird, so more work needs to be done on this issue.

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