; class Aves, order Charadriiformes)
A family of small to fairly large birds, most of which are grey and white, although some have black on the head and wings. The bill is slender to heavy, the wings long and pointed, the tail square or forked, and the feet webbed. The 32 Sterna species have short tails, some being deeply forked with long tail streamers, and some have short crests. Terns are found on coasts, rivers, lakes, and marshes, where they feed on fish, crustaceans, molluscs, insects, and carrion. They nest on the ground, on cliffs, and in trees. The 38–45 Larus species are gregarious and nest colonially; they have yellow, red, or black bills and many have black or dark brown hoods (immature forms are darker). There are 11–17 genera in the family, with about 90 species, most migratory, and found world-wide.
Subjects: Zoology and Animal Sciences.