The yellow-footed gull (''Larus livens'') is a large

gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...

, closely related to the

western gull The western gull (''Larus occidentalis'') is a large white-headed gull that lives on the west coast of North America. It was previously considered conspecific with the yellow-footed gull (''Larus livens'') of the Gulf of California. The western ...

and thought to be a subspecies until the 1960s. It is endemic to the

Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja C ...

Description

Adults are similar in appearance to the western gull with a white head, dark, slate-colored back and wings, and a thick yellow bill. Its legs are yellow, though first winter birds do display pink legs like those of the western gull. It attains full plumage at three years of age. This species is tied with slaty-backed gull for the world's fourth-largest gull species and is one of the largest gulls in the world, being slightly larger than the western gull. It measures in length and spans across the wings.''Gulls: Of North America, Europe, and Asia'' by Klaus Malling Olsen & Hans Larsson. Princeton University Press (2004). . The body mass of this species can vary from .''CRC Handbook of Avian Body Masses'' by John B. Dunning Jr. (Editor). CRC Press (1992), . Among standard measurements, the wing chord is , the

bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Plac ...

is and the tarsus is .

Distribution and habitat

Yellow-footed gulls are native to the

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. Most are non- migratory, but an increasing number have been traveling to

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

Salton Sea The Salton Sea is a shallow, landlocked, highly saline body of water in Riverside and Imperial counties at the southern end of the U.S. state of California. It lies on the San Andreas Fault within the Salton Trough that stretches to the Gulf ...

and southwards to Sonora during nonbreeding periods. Their breeding habitat is the Gulf of California, where they nest, in April, either independently or in colonies. They are found on sandy and rocky coasts or islands, often with little vegetation.

Behavior

The birds are scavengers as well as foragers, feeding on small

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

and

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s, carcases of marine mammals and offal, and preying upon

seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ...

chicks and eggs (including pelican eggs). They sometimes scavenge around waste dumps and docks for refuse but seldom fly far inland. Yellow-footed gulls nest on the beach, a few metres above the upper limits of the highest tides. A pair of birds defends a small

territory A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...

between the nest and the sea. The nest is a scrape in the sand with a meagre lining of seaweed or dry plant material. Usually, three eggs are laid, olive or buff in color with dark blotches, and incubation is probably done by both parents. The young are fully fledged and leave the nest when they are about seven weeks old.

Status

The population is estimated at about 60,000 individuals and appears to be stable, so the IUCN has rated the species as being of "

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

References

* "National Geographic" ''Field Guide to the Birds of North'' ''America'' * ''Seabirds, an Identification Guide'' by Peter Harrison, (1983) * ''Handbook of the Birds of the World Vol 3'', Josep del Hoyo editor, * "National Audubon Society" ''The Sibley Guide to Birds'', by David Allen Sibley,

External links

Audubon: Yellow-footed GullYellow-footed Gull (Larus livens)
{{Taxonbar, from=Q629447 yellow-footed gull Endemic birds of Western Mexico yellow-footed gull Taxa named by Jonathan Dwight