Thayer's Gull (thayeri)

(last update: January 22, 2013)

Amar Ayyash (USA)
Mars Muusse (Netherlands)

Olympic Gull glaucescens x occidentalis 1st cycle (2CY), February 19 2011, Westmoreland Park, OR. Picture: Birdmeister.

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This bird, even though it is facing again and doesn’t show its profile very well, has a blocky head and a honking bill. A good candidate for a 1st cycle Glaucous-winged Gull, but there are some dark streaks in the primaries, which makes it Olympic. Some similarity to Thayer's Gull, but HYBRID GLAUCOUS-WINGED GULL X WESTERN GULL. Besides structural differences (with broad wings and bill size/shape the most obvious), the following characters help separate hybrids from Thayer’s – but a hybrid may resemble Thayer’s Gull in each feature. Hybrids more often have the tertials, tail, and wingtips similar in tone; hybrids have more-diffuse contrast between outer and inner webs on the outer primaries; hybrids often have more solidly dark tails; hybrids often have more advanced molt timing, with extensive scapular molt under way by midwinter (and often with coarser A1 scapular patterns); and hybrids often have duller, dusky pinkish legs.