Species: Lutra lutra
IUCN Red List Status: least concern in England, vulnerable in Scotland and Wales, near threatened globally.
Population Trend: decreasing
Size: male (dog): head and body up to 90cm (36 in); tail 40 cm (16in). Female (bitch) is smaller.
Life-span: uncertain - perhaps 9-10 years in the wild, but many die before they are 4 years old; have lived to be 20 in captivity.
Food: mainly fish - eels are a favourite; also frogs, birds, small mammals, crustaceans, aquatic insects.
Habitat: mainly the area around freshwater lakes, rivers, some coasts - as long as they are undisturbed and there is plenty of cover.
Distribution: the Eurasian otter exists in scattered populations in the British Isles, Europe, Scandinavia, most of Russia and North Africa. In the British Isles, they are found mainly on the coast of Scotland and Ireland, along the Welsh borders, the South-west and East Anglia.
Description: streamline, tapering body and tail, ideal for fast swimming. Brown with paler underparts. Short, strong legs and webbed feet. Small ears and broad flat head. Ears, eyes and nostrils are set on top of head to help surface swimming.
The otter is an appealing, playful animal but they can be very sensitive - it is an offense under the Wildlife & Countryside Act to disturb them or their habitat.
The Wildlife Trust has published a useful guide for spotting otters in the UK - but remember to tread quietly! Other places to see otters on the coast include Shetland, Skye and the Western Isles.