Yellow-footed Gull
Encyclopedia
The Yellow-footed Gull, Larus livens, is a large gull
, closely related to the Western Gull
and thought to be a subspecies until the 1960s.
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. The gull measures 53–58 cm (20.9–22.8 in) in length and weighs 1.17–1.4 kg (2.6–3.1 lb).
Yellow-footed Gulls are native to the Gulf of California
in Mexico
. Most are non-migratory
, but an increasing number have been traveling to California
's Salton Sea
during nonbreeding periods. The population is estimated at about 60,000 and appears to be stable.
Their breeding habitat is the Gulf of California, where they nest either independently or in colonies. The birds are scavengers as well as foragers, feeding on small fish
and invertebrate
s and preying upon seabird
chicks and eggs.
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
, closely related to the Western Gull
Western Gull
The Western Gull, Larus occidentalis, is a large white-headed gull that lives on the western coast of North America. It was previously considered conspecific, the same species, with the Yellow-footed Gull of the Gulf of California...
and thought to be a subspecies until the 1960s.
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. The gull measures 53–58 cm (20.9–22.8 in) in length and weighs 1.17–1.4 kg (2.6–3.1 lb).
Yellow-footed Gulls are native to the Gulf of California
Gulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. Most are non-migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, but an increasing number have been traveling to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
's Salton Sea
Salton Sea
The Salton Sea is a shallow, saline, endorheic rift lake located directly on the San Andreas Fault, predominantly in California's Imperial Valley. The lake occupies the lowest elevations of the Salton Sink in the Colorado Desert of Imperial and Riverside counties in Southern California. Like Death...
during nonbreeding periods. The population is estimated at about 60,000 and appears to be stable.
Their breeding habitat is the Gulf of California, where they nest either independently or in colonies. The birds are scavengers as well as foragers, feeding on small fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate 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...
and invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s and preying upon seabird
Seabird
Seabirds are birds that have 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 environmental problems and feeding niches have resulted in similar adaptations...
chicks and eggs.