Courtesy of Kenn Kaufman
Gull-billed Terns breed along the Atlantic Coast from New Jersey to Florida, along the Gulf Coast from Florida to Mexico, and locally in southern California near the Salton Sea. They also breed in warmer scattered sites across Eurasia, northwestern Africa, and Australia. They winter in the Gulf Coast and points south.
A legend for the range map to the right can be found here.
Gull-billed Terns forage over marshes, pastures, farms, and other open coastal areas. They nest and breed on gravelly or sandy beaches and islands, and winters in salt marshes, estuaries, lagoons, and plowed fields; less frequently along fresh-water areas.
Unlike most terns, Gull-billed Terns have a broad diet; they neither depend on fish, nor plunge-dive for it. Instead they commonly feed on insects, small crabs, lizards, and other prey snatched from the ground, air, or vegetation. The species is also known to eat other tern chicks, and will steal fish from other terns in mixed nesting colonies.
Gull-billed Terns generally nest and breed in small, loosely packed colonies. Most courtship posturing, and feeding displays are performed on the ground. Their nests are shallow depressions on open ground, occasionally rimmed with soil or vegetation. Gull-billed Terns lay average of 3, but up to 7 pale buff eggs, spotted with brown. Both sexes build nests, incubate the eggs, and care for the young. Incubation lasts slightly over 3 weeks. The downy chicks are born able to walk, with their eyes open. They may leave the nest, moving to denser plant cover nearby, only a few days after hatching. They begin to fly at 4 to 5 weeks of age, and may remain with their parents for 3 months.
Gull billed terns are mainly summer residents in the U.S.; some remain throughout the winter on the Gulf of Mexico coast.