Facts about the Western Gull it is essentially a California native.
The Western Gull has the scientific species name Larus occidentalis. The Western Gull species used to be mistaken as part of the Larus Livens or yellow footed gull of the Gulf of California.
This large Western Gull has a dark back, white body, white head, with black and white bars on the tail feathers. The Western Gull has flesh colored legs. The yellow bill has a red spot on the end. The Western Gulls have brown eyes.
Adult Western Gulls reach 22 to 27 inches in length with a wingspan of 51 to 58 inches. The Western Gulls weigh between two and three pounds fully grown. The Western Gull species resembles the slaty backed gull, species name Larus schistisagus.
Juvenile Western Gulls have dark brown heads and bodies, dark wings, and a dark brown tail. When they first hatch, the Western Gulls will have a black bill and dark grey legs. As they age, their head and throat become lighter but remain streaked with darker colors. The bill lightens in color by the second winter.
The Western Gulls feed primarily on fish, krill, squid, and jellyfish. Western Gulls only feed on the surface and do not dive. The Western Gull will feed on sea life carrion like sea lion and seal carcasses. Western Gulls will eat invertebrates in the intertidal zone like limpets, snails, starfish, and cockles. Western Gulls will eat human garbage and take food from humans on the beach. The Western Gulls rarely prey on the young of other bird species. Western Gulls readily steal fish from other birds. Western Gulls drop clams and crabs onto the rocks to open them.
These Western Gulls rarely move inland. The Western Gulls prefer to nest on offshore islands, rocks on the coast or islands inside river estuaries. Western Gulls sometimes nest along coastal cliffs. The Western Gulls will nest around colonies of other sea birds where it will steal eggs and young from. A few nests are near sea lion colonies, where the Western Gull will steal fish if they can as well as eat the bodies of dead sea lions.
Western Gulls build nests out of vegetation on the ground. Western Gulls lay an average of three eggs per clutch. When five or six eggs are found in a nest, this is more commonly due to two females sharing the nest. The eggs are incubated for roughly a month. An average of one chick survives to fledging.
The Western Gulls pair off for the life of the male. Western Gulls live up to fifteen years in the wild.
This Western Gull species sometimes hybridizes with its relative the glaucous-winged gull, scientific name Larus glaucescens.
The Western Gull lives along the Pacific Coast of North America. The largest colony is near San Francisco on the Farallon Islands. Western Gulls are slowly recolonizing islands along the Pacific Coast as lighthouses are automated and essentially abandoned by humans.
The Western Gull species ranges from Baja California to Oregon. The population is concentrated in California year round.
This Western Gull species is of least concern by the IUCN. The Western Gull used to be in greater danger when early settlers of San Francisco harvested eggs from the colonies for food.
This Western Gull species was identified by Audubon in 1839, who later founded the Audubon Society.
The Western Gull species has become a nuisance around the San Francisco Giants stadium, swarming over the field toward the end of the game in the hope of eating food left by visitors.