The smallest and darkest of our geese, the Brent Goose is rather duck-like in flight, and shows a black head, neck and breast. Two forms of brent goose bird occur, Dark-bellied B. (b.) bernicla and Pale-bellied B. (b). hrota. The former has a smoky-grey belly and flanks with a whitish trim on the upper flank feathers. The Pale-bellied has paler flanks, as the name would suggest and although both forms are subject to variation, it has paler underparts contrasting strongly with the black breast. The upperparts are a plain dark grey, the vent or'stern' is white, as is much of the tail. Both forms show a white neck 'flare' on each side. The North American form B. (b) nigricans, also known as the Black Brant, is a vagrant now recorded annually in Britain. This shows very dark underparts with a strongly contrasting white blaze along the flank, plus a more extensive white neck patch.
This species breeds in low-lying Arctic tundra with many pools, but non-breeding birds in Europe favour shallow sea coasts, estuaries and saltmarshes, especially those that are rich in green littoral plants such as Eelgrass Zostera marina, feeding on this and also on algae and saltmarsh plants. It is strongly attached to the intertidal zone and stays faithful to regular routes and stopping places on migration. It can also be found grazing in arable fields close to the coast. Often seen in sizeable flocks, flying in ragged formation.
Although they have a rather limited repertoire and can be quite silent, Brents can be noisy when in a flock and are a familiar sound in winter around parts of our region. They have a single-syllable call - a deep rolling "aaanghrr", a difficult sound to describe but which can be transcribed variously as a soft "raunk", "rronk" or "krrowk". They also give a more gutteral "k'k'rrrot", and when a large number of birds are calling together, either in flight or when resting on water, this becomes a cacophony of far-carrying metallic honking.