More than 40 species of heavily built web-footed seabirds of the gull and tern family Laridae (order Charadriiformes). Several genera are usually recognized for certain specialized gulls, but many authorities place these in the broad genus Larus. Conspicuous and gregarious, gulls are most abundant as breeders in the Northern Hemisphere, which has about 30 species in temperate to Arctic regions. They are mostly colonial ground nesters, and those that breed inland usually go to coasts in winter.