OTTER Lutra lutra

Otters are members of the same family as the badger and stoat - the mustelids - but have adapted to life in the water. Living by rivers, marshes, lakes and estuaries, the otter feeds mainly on fish, with eels seemingly a special favourite. They are largely unselective in what else they eat, taking what is available and easily caught. They will hunt frogs, birds, small mammals, and in coastal waters will prey on crabs and crustaceans.

The otter is a secretive animal, generally nocturnal but active during the day in some remote areas. The male (dog) and female (bitch) occupy separate territories for most of the year except when breeding. The 2 to 3 young are born in an underground breeding den or holt, and share their mother's territory for the first year, after which they usually move away to establish their own. Frequent scent marking with spraints (droppings) is used to mark the territory and this enables courting otters to keep in touch.

The male otter is slightly larger than the female. They both have a brownish-grey coat with a paler underside and a cream coloured throat. Their feet are webbed and their tapering streamlined body ends in a long thick tail. The otter was once hunted for its fur which is unusually dense. The long and stiff guard hairs are coated with oil so that they act as a water repellent. In water, a layer of air is trapped around the otter’s body and this is so effective that the animal’s skin never gets wet and the otter therefore doesn’t lose any heat. After coming out of the water, an otter will spend a long time “drying” itself by rolling in vegetation. They groom regularly, to keep their insulating coat waterproof and in good condition.

Amazingly an otter can swim for 400m underwater without surfacing to breathe. As it dives, its nostrils and ears close automatically, but its eyes remain open allowing it to locate its prey by sight. Otters have relatively poor eyesight, so how do they catch fish in the dark? Fish produce vibrations in the water as they swim. An otter can feel these vibrations with its whiskers which are so sensitive that the otter can chase and catch an eel in dark peaty water.

Populations of otter can be found in Europe, Scandinavia, most of the former USSR and North Africa. In the British Isles, they are found mainly round the coast of Scotland and Ireland and have recently been reported in urban areas. This change in their habitat is directly related to the decrease in pollution of our waterways. As the fish return to river systems, so do otters, so that they have even been spotted on the White Cart river in Glasgow and in other urban river systems.

In our “Brightwater Burn” enclosure, our otters can be seen moving quickly through the water by using strong undulations of their bodies and tails and strokes of their hind feet.