Adult winter Thayer's Gull at Bluffers Park in Toronto
on 12 January 2015. Its identification is based on a combination of
5 characters: (1) It has blackish wingtips approaching the black of
Herring Gull, (2) with large white primary spots that are not
enclosed by black as in Herring Gull, (3) the eye is dark, (4)
the legs are a deep pink, (5) and the mantle shade is similar to
Herring Gull. The head streaking and greenish bill are also typical of Thayer's
in winter. We consider the Iceland-Kumlien's-Thayer's complex to be
one species following Godfrey (1986) in The Birds of Canada and
Snell (2002) in The Birds of North America. Nevertheless, this
individual fits clearly within the Thayer's end of the cline. |