Wednesday, 17 August 2016

Another Juvenile Caspian Gull at Shawell

I had a great session at Shawell this evening. The highlights were three Caspian Gulls: a third-summer (the German colour-ringed bird XNDJ), a second-summer and a new juvenile.

The juvenile Caspian Gull had a pinkish tint to its bill rather than the all black bill of last week's bird and its greater covert pattern differed also. The early evening sun made dig-scoping challenging, but at least I managed to get some record shots.

Juvenile Caspian Gull 17th & 18th August 2016

The upperparts of juvenile Caspian Gulls look very washed out in comparison to the juvenile YLG, LBBG and HG, The head was much paler than the juveniles of all the comparison species. The eye mask of juvenile YLG is missing. The lesser and median coverts are plain brown centered with just plain buff fine edges. The greater coverts show some patterning. The patterning on the greater coverts is variable amongst all four species. The tertials are very fresh, but differ from YLG in having a distinct pale fringe rather than the typical straight white edge mainly on the lower part of the tertial. HG usually have notches on the edge of the tertials. There is of course plenty of overlap between the species, but the small head and long low profile as it rests on the water are typical features of this species. Its underwings were very pale and it had a nice dark tail band contrasting with very white (in the bright light) upper tail.

Juvenile Caspian Gull Underwing

Second-Summer Caspian Gull, Shawell 17th & 18th August 2016

No comments:

Post a Comment