The California Gull (Larus californicus), is a medium-sized gull. There are two subspecies recognized, the nominate species from the Great Basin to central Montana and Wyoming, and the slightly larger, paler L. c. albertaensis with a more northerly distribution, ranging from Great Slave Lake onto the Great Plains of western Manitoba and South Dakota. They are migratory, most moving to the Pacific coast in winter. It is only then that this bird is regularly found in western California.
In California, the California Gull holds special concern on the endangered species list due to declining numbers at its historic breeding colony at Mono Lake. However, this species has colonized the southern portion of San Francisco Bay, where it did not historically nest, and has undergone an incredible population growth (under 1,000 in 1982 to over 33,000 in 2006). They now inhabit large, remote salt-production ponds and levees San Francisco all the way up to the Sacramento area.
Seriously threatened birds that share the same South Bay habitat include the Snowy Plover and California Least Tern, while less-threatened birds including Black-necked Stilts, American Avocets, Forster’s Terns, and Caspian Terns are preyed upon by the abnormally large flocks of California Gulls. Direct culling of the gulls is made difficult by the fact that they have a protective status in California. Efforts are underway to reduce habitat for this species and find other ways to disperse the large numbers of gulls.
Adults are similar in appearance to the Herring Gull, but have a smaller yellow bill with a black ring, yellow legs, brown eyes and a more rounded head. The body is mainly white with grey back and upper wings. They have black primaries with white tips. Immature birds are also similar in appearance to immature Herring Gulls, with browner plumage than immature Ring-billed Gulls.
Their breeding habitat is lakes and marshes in interior western North America from Northwest Territories, Canada south to eastern California and Colorado. They nest in colonies, sometimes with other birds. The nest is a shallow depression on the ground lined with vegetation and feathers. The female usually lays 2 or 3 eggs. Both parents feed the young birds.
These birds forage in flight or pick up objects while swimming, walking or wading. They mainly eat insects, fish and eggs. They also scavenge at garbage dumps or docks. They may follow plows in fields for insects stirred up by this activity.
This is the state bird of Utah, remembered for assisting Mormon settlers in dealing with a plague of Mormon crickets. A Seagull Monument in Salt Lake City commemorates this event, known as the “Miracle of the Gulls”.
Photo Credit: Shengzhi Li