The Brent Goose (Branta bernicla), is a species of goose.
The Brent Goose is a small goose, about 60 cm long and with a short, stubby bill. The under-tail is pure white, and the tail black and very short (the shortest of any goose).
The body is fairly uniformly dark grey-brown all over, the flanks and belly not significantly paler than the back. The head and neck are black, with a small white patch on either side of the neck. It breeds on the Arctic coasts of central and western Siberia and winters in western Europe, with over half the population in southern England, the rest between northern Germany and northern France.
The Pale-bellied Brent Goose appears blackish-brown and light grey in colour. The body is different shades of grey-brown all over, the flanks and belly are significantly paler than the back and present a marked contrast. The head and neck are black, with a small white patch on either side of the neck. It breeds in Franz Josef Land, Svalbard, Greenland and northeastern Canada, wintering in Denmark, northeast England and Ireland.
The geese are gregarious traveling in large, noisy flocks by the hundreds which are hard to miss.
It used to be a strictly coastal bird in winter, seldom leaving tidal estuaries, where it feeds on eel-grass and the seaweed, sea lettuce (Ulva). In recent decades, it has started using agricultural land a short distance inland, feeding extensively on grass and winter-sown cereals. This may be behaviour learnt by following other species of geese. Food resource pressure may also be important in forcing this change, as the world population had risen over tenfold to 400,000-500,000 by the mid 1980s, possibly reaching the carrying capacity of the estuaries. In the breeding season, it uses low-lying wet coastal tundra for both breeding and feeding. The nest is bowl-shaped, lined with grass and down, in an elevated location, often in a small pond.
The Brent Goose is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.