Little Gull (Larus minutus)
Alviso Environmental Center, Santa Clara County, California
17 May 1998

Today I took my ornithology class to Alviso where we were fortunate to locate the immature Little Gull which has been present off and on since 8 May when found there by Steve Rottenborn. It was on a narrow island in the salt pond A16 just north of the Environmental Center where it was with a small group of immature (1st summer) Bonaparte's Gulls.

I first noticed it because of it's stronger dark cap and more prominent post ocular spot combined with with stronger dark markings on the outer wing and greater coverts. Through the scope we could see that the bird was slightly smaller than the adjacent Bonaparte's Gulls with a noticeably smaller black bill and decidedly shorter, duller colored legs. The mantle was pale gray and the rest of the body was white.

When the bird flew it showed a striking "M" pattern across the upper wings, very different pattern from the Bonaparte's. The outer primaries were black with white inner webs visible on the spread wing. The greater coverts were black angling diagonally toward the scapulars contrasting strongly with the white inner primaries and secondaries. The underwings were white and there was no dark trailing edge to the wing as in the immature Bonaparte's Gulls. Thus the pattern was more like a Black-legged Kittiwake than a Bonaparte's. The wings seemed shorter and more rounded and, in flight, the bird seemed even smaller than when standing. The body appeared more torpedo-shaped compared to the better proportioned Bonaparte's; heavier at the front and with no obvious neck.

The bird flew over to Salt Pond A18 and out of sight. We did not see it again.

Account written 17 May 1998.
--
Joseph Morlan
380 Talbot Avenue #206
Pacifica, CA 94044