These four juvenile Mongolian
Gulls Larus (c?) mongolicus were photographed at
Olkhon Island, Lake Baikal on August 16, 1997 by Geert Groot Koerkamp.
Geert comments: "Juveniles are variable, but on most birds
I have seen in August the bill is completely black, wings show
a clear window on the inner primaries, with rather light greater
coverts (i.e. no greater covert bar), and tail is white with clear-cut
black band and white tips to the tail feathers; tertial pattern
is highly variable, as can be seen from the photos; underwing
is not white as in typical cachinnans and reminds one more
of michahellis. it strikes the eye that the underparts
are rather dark in comparison with, for example, juvenile cachinnans
or michahellis." - note that barabensis does
have more extensive markings on the underparts, compared to cachinnans,
but not as extensive as on these mongolicus:
- althought it appears identical, Geert assures me that the next
image is of a different bird:
