Why does the otter need help?
In the late 1950's and early 1960's otters underwent a sudden and catastrophic decline throughout much of Britain and Europe. The cause was probably the combined effects of pollution and habitat destruction, particularly the drainage of wet areas. Persistent pesticides, which otters accumulate in their bodies because they are at the top of the food chain, were in widespread use at the time. Otters are now making a gradual return to our rivers. Populations are recovering, but the otter is still vulnerable.

How do I recognise an otter?
- brown fur on their back and a pale underside
- long slender bodies with a tapered thick tail
- a body length of about 1m from nose to tail
- webbed feet with five toes
- sensitive whiskers on a broad muzzle that can sense vibrations from fish in the water
- small ears and small eyes (but they have very good eyesight)
- a male otter typically weighs about 10kg while the female weighs 7kg

Otters are sometimes confused with the feral American Mink, although mink are much smaller (cat size or smaller) and swim more buoyantly, with their back well above the water surface.

Where do you find otters?
Otters lie along rivers, lakes and occasionally estuaries and coasts. They can use a variety of habitats found within the river floodplain such as reedbeds, fen and woodland. Coast-living otters need fresh water to clean salt from their fur, otherwise they will lose the ability to keep themselves warm. Otters are generally nocturnal and sightings are rare.

What do they eat?
Otters feed mainly on fish. Slow-moving coarse fish are generally eaten as they are easier to catch, but otters will eat a variety of fish depending on what is available. In East Anglia, otters especially favour eels and in the spring frogs are important food items. Otters occasionally take water birds such as coots, moorhens and ducks.

How can I tell if there are otters present?
Otters deposit faeces (known as spraints, which have a characteristic sweetly fishy smell) in prominent places within their ranges. These probably serve to mark an otter's range and help neighbouring animals keep in social contact with one another.

Mink droppings are usually twisted in shape and smell very unpleasant - a sure test if you are brave enough!

Otter footprints have five toes and are about 50 mm across - compared to dog or fox footprint, which only have four toes and are generally smaller. Mink also have five toes but are much smaller.

Breeding
Females breed when they are about two years old. Mating can take place at anytime of year with two or three cubs born in a den, called a holt. These can be within tree root systems, a hole in a bank or under a pile of rocks. About ten weeks elapse before the cubs venture out of the holt with their mother, who raises the cubs without help from the male. Initially females catch food for their cubs, which remain with her for about six months to a year. Otters can live to be ten years old, although few survive more than five years.

Threats to otters
Although populations are recovering, the otter remains threatened by a number of factors:
- a lack of suitable habitat along rivers to provide safe and secure areas for otters.
- poor water quality and pollution means insufficient food for otters.
- roads are a major threat to expanding otter populations. Otters are killed as they move out of existing strongholds and re-colonise their old haunts.
- other incidental deaths can occur in nets to catch eels, known as fyke nets.
- disturbance from increased use of water.

Legal protection
Otters are strictly protected by the Wildlife and Countryside Act (1981) under which it is illegal to kill or remove an otter from the wild without a licence; damage or obstruct a holt; or disturb an otter in its resting place. A licence may be required to carry out management works that may disturb a nesting otter.

Conservation
Otters require clean rivers with abundant, varied supply of food and plenty of bankside vegetation offering secluded sites for their holts. Some are known to use 40 km or more of river habitat. Riversides often lack the appropriate cover for otters to lie up during the day. Such areas can be made more attractive to otters by establishing 'otter havens', which may include planting bankside trees, leaving areas as undisturbed scrub and leaving uncultivated buffer zones along watercourses and managing riverside land sympathetically. Wet grassland, fen, reedbeds and their associated dyke networks are also important habitats for otters.

For further details or fact sheets contact:
Penny Hemphill, Suffolk Wildlife Trust, Brooke House, Ashbocking, Ipswich, IP6 9JY
Tel 01473 890089 or email penny.hemphill@suffolkwildlifetrust.org