Slaty-backed Gulls Larus schistisagus
March 15th 2005 Choshi Chiba Japn
2nd winter Glaucous-winged Gull, 1st winter Slaty-backed Gull.
Slaty-backed Gull, Glaucous Gull
1 2nd winter Vega Gull, 2 1st winter/summer Slaty backed Gulls.
Note the brownish, less contrasty upper surface of the wings.
A bleached, whitish Slaty-backed Gull with a Glaucous Gull.
Same individual as above
A relatively darkish Slaty-backed Gull for this time of year. This overall coloration resembles Vega Gulls. But its darkish new scapulars and pale underside of P10 seem to point toward Slaty-backed Gull.
The left wing of the same individual. Compared to Vega Gulls, it shows less contrast between outer and inner primaries.
A presumed late-hatched Slaty-backed Gull in center.
This individual resembles smithsonianus especially in the above photo. But its tertials, secondaries, primaries and tail are not strongly dark. I can find no particular differences from fresh juv/1w Slaty-backed Gulls in autumn.
Same individual as the three photos above.
Vega Gull Larus vegae
on the same date
Note the overall appearance resembles argentatus/argenteus.
Note the blacker outer primaries, secondaries, and tail band compared to Slaty-backed Gulls. Dozens of Vega Gulls in March 7th at this good point were mostly replaced by dozens of Slaty-backed Gulls, though abundant Vega Gulls are still present in this big fishing port. To see more Vega Gulls on March 7th, Click here