Abundant in the West. Resembles the smaller Ring-billed Gull (both may have yellowish green legs or not), but note the darker mantle, darker eye, and red and black spot
on the lower mandible (not a black ring). Shows more white in wingtips than the Ring-bill does.
Seacoasts, lakes, farms, urban centers.
Breeds in the interior at lakes and marshes, often foraging for insects around farms, plowed fields. Some winter inland around major lakes and rivers, but most are coastal at that season, frequenting beaches, docks, garbage dumps, fields. Sometimes commo
n well offshore in winter.
Varied; includes insects, fish, eggs, refuse. Summer diet inland is mostly insects; also worms, spiders, rodents, eggs
and young of other birds, and carrion. On coast, eats fish and other marine life, also scavenges for refuse around garbage dumps, fishing piers.
Behavior: Forages while walking, wading, swimming, or flying. May hover and dip down to pick items from surface of land or water. Sometimes follows plow in farm fields to pick up insects exposed in the furrows.
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern. [conservation status from birdlife.org]
Breeds in colonies, sometimes very large, and sometimes mixed with Ring-billed Gulls or other birds; the nests may be quite close together. Court
ship involves various postures and calls; male displays with upright posture, -choking- motions. Also courtship feeding, with male feeding female.
Nest: Site is on ground near lake or marsh, often on island. Nest (built by both sexes) is shallow depression, usually lined with weeds, grass, debris, feathers.
Clutch 2-3, sometimes 1-5. Clutches of more than 3 result from 2 females laying in same nest. Eggs brown, olive, gray, or buff, blotched with dark brown or gray. Incubation by both parents, 23-27 days.
Young: May leave nest when a few days old, but remain in immediate area. Both parents feed young, by regurgitation. Young can fly at about 45 days after hatching.
Mainly western North America, east to central North Dakota. Migration:
From breeding grounds in interior, most migrate west or southwest to Pacific coast. Surprisingly few move south to Gulf coast; extremely rare east to Atlantic coast. Birds too young to breed may remain along Pacific coast through the summer.
- spanwidth min.: 125 cm
- spanwidth max.: 135 cm
- size min.: 47 cm
- size max.: 54 cm
- incubation min.: 23 days
- incubation max.: 27 days
- fledging min.: 2 days
- fledging max.: 4 days
- broods 1
- eggs min.: 1
- eggs max.: 4
- Conservation Status
- Larus californicus californicus
- nw USA
- Larus californicus albertaensis
- c Canada, nc and nw USA
- Larus californicus
- NA, MA nc, w