California gull

Description:

A medium sized gull

Notes:

In California, the California Gull recently held the protected status California Species of Special Concern due to declining numbers at their historic California breeding colony at Mono Lake. However, in recent decades this species has begun to breed in the southern portion of San Francisco Bay, where it did not historically breed, and has undergone exponential population growth. These California Gulls now inhabit large, remote salt-production ponds and levees and have a very large food source provided by nearby landfills from San Francisco, San Jose and other urban areas, all the way up into the Sacramento area. The South Bay California Gull population has grown from less than 1,000 breeding birds in 1982 to over 33,000 in 2006. This population boom has resulted in large resident flocks of gulls that will opportunistically prey on other species, particularly the eggs and nestlings of other birds. 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 also preyed upon by the abnormally large flocks of California Gulls. Efforts are underway to reduce habitat for this species and find other ways to disperse the large numbers of gulls. (Ackerman et al. 2006)