L. argentatus smithsonianus
October 23th 2002 Sakawagawa-river Odawara Kanagawa Japan
When it came flying above me, it resembled Vega Gull rather than Slaty-backed Gull because of its long-winged structure and blackish tips to the underwings. But soon, it lost altitude, and showed me the upperside that has broad tail band and dark greater-coverts.
The smithsonianus, and a Slaty-backed
The smithsonianus, and another Slaty-backed Gull (left)
Note their leg colors. The legs of the smithsonianus was obviously paler than deep pink of the surrounding 5 or 6 1st winter Slaty-backed Gulls.
Its face impression resembles Vega
Gull, rather than Slaty-backed Gull.
Note the black inner web of P10.
It is usually obviously paler in Slaty-Backed Gulls.
Uniformly dark underparts and underwing