About Larus livens Dwight, 1919
Adults of Larus livens (yellow-footed gull) are similar in appearance to the western gull. They have a white head, dark slate-colored back and wings, a thick yellow bill, and yellow legs. First winter individuals have pink legs, matching the leg color of first winter western gulls, and the species reaches full adult plumage at three years of age.
This species is tied with the slaty-backed gull as the fourth-largest gull species in the world, and is one of the largest gulls globally. It is slightly larger than the western gull. It measures 53 to 72 cm (21 to 28 in) in total length, with a wingspan of 140 to 160 cm (55 to 63 in). Body mass ranges from 930 to 1,500 g (2.05 to 3.31 lb). Standard measurements are: wing chord 40 to 46 cm (16 to 18 in), bill 5.0 to 6.2 cm (2.0 to 2.4 in), and tarsus 5.9 to 7.5 cm (2.3 to 3.0 in).
Yellow-footed gulls are native to the Gulf of California in Mexico. Most individuals are non-migratory, but an increasing number travel to California's Salton Sea and south to Sonora during nonbreeding periods. Their breeding habitat is located in the Gulf of California, where they nest in April either independently or in breeding colonies. They occupy sandy and rocky coasts or islands, most often sites with little vegetation.
