Identification Photos: Western Gull, Larus occidentalis: The Western Gull is a large, white-headed gull that lives on the West Coast of North America. It is almost identical to the Yellowfooted Gull, Larus livens, found in abundance in the Sea of Cortez, Mexico, and can also be easily confused with the Slatybacked Gull, Larus schistisagus.

The Western Gull is considered to be a large gull, reaching 2 feet in size. It has a white head and body and gray wings. The characteristic beak is yellow with a red subterminal spot, which is used by chicks for pecking to stimulate feeding.
Exclusively a marine gull, the Western Gull is seldom found inland. It nests on islands both offshore and within estuaries and in rocks along the coast. Large colonies of Western Gulls are found on Alcatraz Island and in the Farallon Islands.

Within its colonies, Western Gull forms lifelong pairs that aggressively defend established territories for the duration of the lifespan of the male. Nests are constructed on the ground using vegetation. Three eggs are laid and incubated for a month; mortality is high and normally only one chick survives.

The Western Gull cannot dive and feeds exclusively on the surface, both at sea, taking fish and invertebrates such as krill, squid and jellyfish, and on land feeding on limpets, seal and sea lion carcasses, and snails.

Western Gull is also found in dumps and takes handouts from people at marinas and beaches. It typically lives 15 to 25 years.

Western Gulls range from British Columbia to Baja California, Mexico. Due to its colonization on the coast of California, it is well studied. From a conservation perspective its limited range is of concern, but it is not considered to be threatened. The Western Gull is currently vulnerable to climatic events and oil spills.

Note: the Western Gull played a leading role in Alfred Hitchcock’s famous movie “The Birds.”

Western Gull, Larus occidentalis: Very abundant in Baja California, Mexico during certain times of the year. It can be a pest to the shore angler as it will, at the blink of an eye, steal unguarded, and even protected, bait and catch. Description courtesy of John Snow. Photo courtesy of Carol Snow.