Northern Prairie Wildlife Research Center
HABITAT: Inhabits barren islands on fresh, brackish, or alkaline lakes, shores of lakes or ponds, and marshes. Favors sites with low, sparse vegetation. Outside the breeding season it occurs on seacoasts, bays, estuaries, mudflats, irrigated fields, and other agricultural lands.
SPECIAL HABITAT REQUIREMENTS: Open sandy or gravelly lakeshores or islands.
NEST: A colonial nester, often nesting in mixed colonies with the ring-billed gull. Avoids dense herbaceous cover, and constructs its nest in a scrape on the ground in elevated, boulder-strewn areas.
FOOD: Forages opportunistically on shortgrass plains and cultivated lands for a wide variety of foods, including insects, carrion and garbage, earthworms, young birds, bird eggs, and rodents.
REFERENCES: Greenhalgh 1952, Johnsgard 1979, Vermeer 1970.