Kittiwake Rissa tridactyla, adult in flight

Gulls and terns

Gulls are small to large seabirds, many of which also live inland for at least part of the year; some are strictly marine. Most are grey, black and white when fully mature, but extensively marked with various shades of brown during from one to four years of immaturity.

Terns are small to medium birds, often smaller and slimmer than most of the gulls. All are migratory, often seen outside their breeding areas in spring and autumn, but absent from Europe in winter. There are two main groups, the ‘sea’ terns (not always strictly marine), which look pale grey and white except for a black cap in summer, have long tail streamers and dive to catch fish, and the ‘marsh terns’, which are blunt-tailed, almost black underneath in summer, and dip to pick their food from the surface without diving.