Thayer's Gull (thayeri)(last update: January 22, 2013) |
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Thayer's Gull 1st cycle (1CY), December 2009, California, US. Picture: Chris Gibbins.Visit: Chris's weblog. Extensive dark central tail-feathers and pale window on inner primaries. Heavily / densely patterned uppertail and undertail coverts. Note pale crescents on primary tips. |