I spent the morning of Friday 17 November 2006 birding in the Imperial Valley of Imperial County, California, my only notable sightings being a wintering Solitary Sandpiper (Tringa solitaria) 5.5 km west of Seeley and a White-throated Sparrow (Zonotrichia albicollis) frequenting a feeder near the southeast corner of El Centro.
In the afternoon I birded eastward along the south shore of the Salton Sea from the vicinity of the New River mouth, seeing the expected number and variety of waterbirds. The weather was clear and calm, with the temperature approaching 80° F in the afternoon. At about 1500 hr I arrived at the boat-launch ramp at the southwest corner of Red Hill and drove to the hill’s westernmost point for optimal viewing of the gulls loafing along the west shore.
As I cautiously drove west on the north dike to the boat-launch channel, my attention was drawn to a small white gull on the water about 50 feet to my right. My initial reaction was that the gull was a Ross’s Gull (Rhodostethia rosea), but at the same time knew that I was at the south end of the Salton Sea so must be mistaken. However, upon more careful study with binoculars, I was unable to make this bird into an aberrant Bonaparte’s Gull (Larus philadelphia) or an odd looking Little Gull (L. minutus)—it was indeed an adult Ross’s Gull in basic plumage.
At this time the gull flew a short distance to the shore about 100 feet to the northeast and began actively picking insects from the surface of the wet mud.