Thayer's Gull (thayeri)

(last update: January 22, 2013)

Thayer's Gull 1st cycle (2CY), mid-January 2014, central California, US. Picture: Amar Ayyash.

Visit: Amar's blog for many more images!

Present flock of about >600 birds (170 1st cycles, 100 2nd cycles, 40 3rd cycles, 350 adults).

Blackish bill, dark iris.
First gen flight feathers; primaries with neat fringes confined to the tip of each feather.
Typically, tertials have solidly brown centres, but feathers notched in this individual. Dense barring on upper and undertail coverts, tail most dark with some proximal vermiculation on outer rectrices.
Typically scapulars are three-tones: pale brown centre, dark sub-terminal line and pale fringe. Here, a few upper scapulars missing.

This bird still almost completely juvenile (single upper scapscurrently replaced), worn in scapulars and coverts. Rather obvious Herring Gull-like notching on greater coverts ("piano-key pattern") and bird with surprisingly 'high stance', long exposed tibia, where Thayer's normally look rather short-legged.