A selection of 1 cy Thayer's Gulls, Half Moon Bay, California, 14 Dec 28

This post shows a selection of subtly different Thayer's Gulls. Some show the accepted phenotypic characters of this taxon, but others (e.g. the second bird) would be rather difficult to identify with 100% confidence out of range.

Half Moon Bay, California (13 December)

Peregrine Falcon. This bird spooked the gulls and actually took a California Gull...

Peregrine, with its prize

Ring-tailed 'Marsh Hawk'

Mew Gull

California Gull (2 cy)

California Gull (2 cy)

Western Gull (adult)

Mew Gull (1 cy). A real cracker

Glaucous Winged Gull

California Gull