Can you ‘do’ first winters?
Found myself asking that question once again. Yesterday came across the bird below at Catcliffe Flash, Sheffield. It’s a first winter Common Gull- no argument. However unlike many/most first winters normally seen in the U.K. This one has couple of extra dark bits. These are:
- Rump and uppertail unusually well barred with brown
- Dark mottling over white areas of the tail
- Dark barring on longest auxiliaries
Note the tail band on this bird isn’t that broad: On some Common Gulls wintering in Japan, the black tail band is wide enough to reach the edge of the uppertail coverts. On others however the rump and tail pattern is very similar to this (Sheffield) bird.
I think the third feature (auxiliary barring) is not uncommon, but the tail and rump pattern on this bird seemed to be to be a bit unusual.
I have an assumption which may or may not be correct.
The eastern most taxa Kamchatka Gull kamtschatschensis has the most dark on the tail, most barred rump and most barring in underwings coverts. My assumption is that as you go ‘east’ the dark pigmentation increases in Common Gull, terminating in kamtschatschensis.
Thus, such individuals as the bird below might be identifiable heinei - ‘Russian’ or Siberian Common Gulls. Yes or no?
Any thoughts? Input very welcome! How common is this tail and rump pattern combo in Western Europe?
All photos Catcliffe Flash, Sheffield, 21 December 2010.