Otter (Lutra lutra)

Otter

UK History

Formerly widespread throughout the UK, the otter underwent a rapid decline in numbers from the 1950's to 1970's and was effectively lost from the midlands and south-eastern counties of England by the 1980's. Throughout the 1950's and 1960's, even though otters were under serious threat from river pollution (pesticicde run-off) and degradation of waterways, hunting continued unabated. According to the hunts own records between1958 and 1963, 1065 otters were killed.

Results from national surveys now show that otter populations are rising - though numbers are still low, and therefore vulnerable.

UK Status

In the British Isles, otters are found in fresh and salt water. The bulk of the UK population is found around Scotland’s coast.

Global Status

Found throughout Europe, as far north as the Arctic Circle, north Africa and parts of Asia.

The Eurasian otter is classified by the IUCN (International Union for the Conservation of Nature) in the Red Data Book as 'vulnerable to extinction'.

Biology

Otters breed all year round with a preference for spring and late autumn. They have a gestation period of about 63 days, after which two or three cubs are born. The cubs are weaned after 3 - 4 months, but remain with their mother for 12 - 15 months and reach sexual maturity after two years. Most will only live for around 4 years although some may survive between 8 - 12 years.

Apart from fish, otters also feed on crustaceans, water birds, frogs and voles.

Issues with humans

Otters were once hunted for their fur and were thought of as a pest, competing with fishermen for fish. In spite of these pressures, otters were widespread throughout Britain and the population remained steady until the 1950s when it declined rapidly due to pollution and disturbance.

Pollution of freshwater habitats has probably had the greatest impact on otters. Pesticides, used extensively during the 1950’s, were washed off the land into rivers and contaminated fish leading to a build up of lethal poisons in otters. Although most of these pesticides have been restricted since 1962, otter numbers have not increased significantly.

Since the 1950s, riverside habitats have also been drastically changed by farming and building techniques and have become far too ‘tidy’ with fewer available holt sites. Watersports have also added to the disturbance of waterways.

Otters have been protected by law since 1981 but a major threat to them now is traffic on the roads. Almost 70 per cent of otters found dead in Britain are killed on the roads. Most of these are males, following established routes through their territories which have been crossed by busy new roads.

Future Outlook

It appears that otters are making a slow return to some of their former range across lowland England.

Small numbers have been bred in captivity and released into favourable habitat in co-operation with land-owners. Artificial holts have also been built where natural cover is inadequate. There are signs that these measures will help to re-establish otter populations in at least some of their former haunts.

More bridges and otter corridors are required to improve the animals' road safety and waterways need to be managed to provide suitable cover and food.

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