III.

Life Cycle

Gulls breed colonially, mostly on the flat ground of beaches, marshes, or riverbeds, where they build simple, shallow, grass-lined nests. Several species nest on ledges of cliffs, notably the kittiwakes. The clutch consists of two or three greenish-brown, speckled eggs, which take 20 to 30 days to incubate. At hatching the chicks have down feathers, and the eyes are open. Chicks can stand but are dependent on their parents for food and warmth. The parents share in incubation of the eggs and in the brooding and feeding (by regurgitation) of the chicks, which fledge between four and six weeks after hatching. Gulls have been known to live as long as 40 years in captivity and as long as 36 years in the wild.