A gull is a gull—but what kind? About fifty gull species (Larus spp.) are recognized worldwide and around twenty species visit or live in places in California such as the San Francisco Bay Area . The current Bay Nature issue features an instructively illustrated table of nine seagull species , providing an excellent source for comparing gull species as adults as well as in their first, second and third year. During the first years the plumage typically changes from brown to the gray or white color that gull feathers show in maturity. Successful gulling depends on the description of shape, color and patterns of the bills. Differences are nicely illustrated in the “gull-ability table.”
The Western gull and the California gull nest in the Bay area, where they are seen year-round . Others are seasonal residents such as Heermann's gull (Larus heermanni), which mostly stays in S. F. Bay habitats during summer and fall months. This bird species is named after physician and naturalist Adolphus Lewis Heermann (1827-1865) , who also is remembered in the name Dipodomys heermanni for the Morro Bay kangaroo rat. Names of other gull species indicate size (Bonaparte's gull), bill features (ring-billed gull) and diet (Herring gull). Some species interbreed, challenging our gullability even further.
Keywords: ornithology, avian species, migratory birds, birding
References and further gulling
 Joe Eaton: A Squabble of Gulls • Grudging Respect for Hardy Survivors. Bay Nature October-December 2010, pp. 30-35.
 John Muir Laws: Test Your Gull Ability. Bay Nature October-December 2010, page 36.
 Bo Beolens, Michael Watkins and Michael Grayson: The Eponym Dictionary of Mammals. The Johns Hopkins University Press, Baltimore, 2009; page 183.