Bonaparte’s Gulls (Chroicocephalus philadelphia) are seen on the coast and throughout the province during migration in spring on route to their northern breeding grounds and in late-summer/fall when flying to the western and southern US coast and Mexico, where they spend the winter. Some overwinter on the South Coast of BC and some breed in Northern BC where they nest in trees; unlike most other gulls. The adults have dark black heads during the breeding season, orange legs, black wing tips, white chests and grey wings. The head of the juveniles is lighter and often streaked with white. The adults have a white head with a dark spot behind the eye during the non-breeding season. They are often seen in groups, sometimes in the hundreds, and feed on small fishes, crabs and other crustaceans.