Wednesday, October 5, 2011

American Black Tern

Popped into Covenham reservoir on the way back south.
After some scanning a likely candidate was picked up, typically at the opposing corner of the quite sizeable reservoir. As I walked around it didnt seem to be getting any closer, it was also working its way around the reservoir at the same pace I was! Eventually after probably walking two thirds of the way round I eventually caught up with it.
Fortunately it was feeding quite close in but unfortunately the light was starting to go and the sun was low and now directly opposite.
From a distance it did appear generally darker than a typical niger and as one got nearer features to confirm its identity could be gleaned.
One of the most talked about features is the grey flanks which should be white in niger. Another feature that can be seen here are the greyish underwing coverts which are usually clean white in niger

Breast patch larger than niger, merging into flanks

Rump dark grey as opposed to a more mid grey.
On niger a black crown would extend to a black nape but on this bird the crown is grey and the nape is white. Upperwings of surinamensis are a fair bit darker.

Underwings look quite white in this shot but the dark flanks still obvious

Juv Common Tern

Light really going now but why not get another photo of a Greenland type Wheatear