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).

Overall paleness of the bird and pale base of bill slightly odd; birds like this probably represent the paler end of the Thayer's spectrum.

Blackish bill with pale base, dark iris.
First gen flight feathers; primaries with neat fringes confined to the tip of each feather.
Tertials have solidly brown centres, 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.

This bird still almost completely juvenile (single upper scaps replaced), worn in scapulars and coverts. Small bill and high forehead may suggest female.