Slaty-backed Gulls Larus schistisagus
February 3rd 2007 Choshi Chiba Japan

A typical advanced 1st winter. Note the post-juvenile scapulars, strongly worn tertials/coverts, and whitish head-breast.

A rather uniform individual.

A fresher individual, upperparts mostly juvenile plumage.

Note the abnormally short P9. This P9 might be the 2nd generation which came up instead of the lost juvenile P9 in an accident.

Male-type (left), female-type (right). Both have heavily worn tertials and coverts, unlike Vega Gulls.

The scapulars and coverts resemble smithsonianus. But note the stubby overall structure, brownish short primaries and deep pink legs.

A relatively whitish individual, mostly worn juvenile plumage but some mantle and upper scapular feathers.