Best time to see: Oct to mid Apr

Key facts

Small very dark goose of estuarine habitat, once endangered but increasing as a result of conservation action

Breed on the arctic tundra, dark-bellied in northern Russia, pale-bellied in Canada and Greenland

Common winter visitor to UK: dark-bellied race comes to south-east England and continent, pale-bellied to Ireland

Recognition

Dark-bellied has black face with white flash on black neck; white rear end with belly as dark as breast; 55–60 cm

Leave their breeding grounds by mid-September, arriving in Essex in large flocks in early October

On arrival feed on eel-grass beds on the mud; later move to cereal fields and grassland near the estuary