Figure 151. Perhaps the most widely seen Black-headed Gull recorded in California—with competition from a bird present during eight straight winters at the Stockton sewage treatment plant in San Joaquin County—was this one, which spent six consecutive winters in Santa Barbara, Santa Barbara County. This 14 December 1992 portrait is from the bird’s first winter, as indicated by retained juvenal feathers (1992-292; Don DesJardin).

 

Figure 152. Distribution of 22 Black-headed Gulls accepted through 2003, all coastal except for two at Stockton, San Joaquin County.

 

 

 

 

 

 

 

BLACK-HEADED GULL Larus ridibundus Linnaeus, 1766

Accepted: 22 (71%)	Treated in Appendix H: yes
Not accepted: 9	CBRC review: all records
Not submitted/reviewed: 1	Color image: none

In the Old World, this gull breeds abundantly from Iceland eastward across Eurasia. Mlodinow and O’Brien (1996) summarized the species’ New World status and distribution. Subspecies L. r. ridibundus breeds regularly in western Greenland and Newfoundland, and casually elsewhere in the Atlantic Provinces and the Northeast. Small numbers winter regularly south to New England, with a few scattered birds typically found elsewhere along the Atlantic coast. Migrants (particularly in March and April) and non-breeding wanderers occur at other seasons, mostly along the coast (south to about North Carolina), less so on the eastern Great Lakes. This is a very rare species elsewhere in the continent’s interior, with only a handful of inland records from the Great Plains westward. The weakly differentiated L. r. sibiricus, which breeds in northeastern Siberia and winters in eastern Asia, is not recognized by some authorities (e.g., Vaurie 1965, Cramp and Simmons 1983), but was regarded as valid by Olsen and Larsson (2004). Birds presumably attributable to sibiricus migrate regularly and in very small numbers—mostly in spring—through the western and central Aleutian Islands; fewer records come from islands of the Bering Sea. The species occurs casually on the Alaskan mainland and southward along the Pacific coast and has twice reached Hawaii. The southernmost New World records are from Cuba, Trinidad, Surinam, and French Guiana.

The first Black-headed Gull found in California was an adult present 23–24 January 1954 at the Richmond inner harbor in Contra Costa County. Fourteen years elapsed before the next occurrence, and, although the pace later quickened, periods of up to three consecutive years have passed without a record. Most records involve birds along the coast among flocks of Bonaparte’s Gulls, and they span the seasons, although none are from May—a month when many Little Gulls have been recorded. About half of the state’s Black-headed Gull records involve wintering birds, including one of an adult that returned for eight consecutive winters (1979–1986) to the sewage treatment plant at Stockton, San Joaquin County. For several years this individual associated with the same large flock of Bonaparte’s Gulls that held up to four Little Gulls, and from 24 March to 13 April 1985 it was joined by a second Black-headed Gull. The species is otherwise unrecorded in the state’s interior (Figure 152). California lacks a specimen, but in light of this gull’s extreme rarity in the interior West, most or all of the state’s records presumably involve birds from Siberia rather than from the East.

The record of a first-winter bird seen at three sites in Ventura and Los Angeles Counties during winter 1980/1981 perfectly illustrates the value of photographic documentation: were it not for photos revealing a tail pattern unique to this roving bird, its stay on the south coast might well have been attributed to three different individuals (Binford 1985).