Adult Cachinnans?
Posted: Mon Sep 13, 2010 8:20 pm
Hello,
this gull swam in a small lake in northern Germany together with adult Herring Gulls. I presume that it is a Caspian Gull but want to hear your opinion, because I just saw it swimming. Compared to the Herrings it had small blackish eyes, a completely white head (the Herrings were almost in winter plumage), a different head shape and a small gonys spot. Furthermore, I think the outermost primaries are still growing. What I wondered about was the slightly darker greytone of the mantle and coverts compared to Herrings.




Thanks for your help,
Oliver
this gull swam in a small lake in northern Germany together with adult Herring Gulls. I presume that it is a Caspian Gull but want to hear your opinion, because I just saw it swimming. Compared to the Herrings it had small blackish eyes, a completely white head (the Herrings were almost in winter plumage), a different head shape and a small gonys spot. Furthermore, I think the outermost primaries are still growing. What I wondered about was the slightly darker greytone of the mantle and coverts compared to Herrings.




Thanks for your help,
Oliver