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

gull Gulls, or colloquially seagulls, are seabirds of the subfamily Larinae. They are most closely related to terns and skimmers, distantly related to auks, and even more distantly related to waders. Until the 21st century, most gulls were placed ...

, 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 and the Pacific Ocean. The western gull ranges from British Columbia, Canada, to Baja California, Mexico. It was previously con ...

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

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

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 Pl ...

is and the tarsus is .

Distribution and habitat

Yellow-footed gulls are native to the

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

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

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Salton Sea The Salton Sea is a shallow, landlocked, highly salinity, saline endorheic lake in Riverside County, California, Riverside and Imperial County, California, Imperial counties in Southern California. It lies on the San Andreas Fault within the S ...

and southwards to

Sonora Sonora (), officially Estado Libre y Soberano de Sonora (), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is divided into Municipalities of Sonora, 72 ...

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

scavenger Scavengers are animals that consume Corpse decomposition, dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a he ...

s as well as foragers, feeding on small

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

and

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

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

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

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, belonging or connected to a particular country, person, or animal. In international politics, a territory is usually a geographic area which has not been granted the powers of self-government, ...

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

fledge Fledging is the stage in a flying animal's life between egg, hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnera ...

d and leave the nest when they are about seven weeks old.

Status

The population is estimated at 60,000 individuals and appears to be stable, so the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

has rated the species as being of "

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

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 Gull

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