American Herring Gull (smithsonianus)

(last update: October 30, 2015)

Slaty-backed Gull (schistisagus) 1st cycle (2CY), March 12 2012, Choshi, Japan. Picture: Michiaki Ujihara.

Please visit Japanese Gull site for many more pictures!

Slaty-backed Gull generally has much black in the tail; either a broad tail-band, but often an all-dark tail like Western Gull. There is variation in extent of the proximal white on the outer rectrices. Their overall coloration looks less contrasty and more concolorous than Vega Gull do, but on the other hand usually gives a patchy, uneven impression compared to Thayer's and Glaucous-winged Gulls.