The Eurasian Otter (Lutra Lutra) is one of the UK’s most famous mammals but is also one of the most scarce having been effectively wiped out from much of it’s traditional range between the 1950 to 1990. Fortunately this massive decline was noticed in time so that steps could be taken to reverse it. A combination of pollution in the waterways, increased traffic on roads and decline in fish stocks forced this aquatic mammal out into the wilds away from major river systems, towns and cities.
Pesticides introduced in the 1950’s led to pollution at the very bottom of the food chain which worked its way all the way through to the otters at the top. Much of these pesticides have now been phased out so the threat from poor water quality and poisoned food is much reduced.
Today otters are found in reasonable numbers in North Western Scotland, Cumbria, Devon and Cornwall. They have also been re-introduced to other counties around the UK and population numbers have started to increase, although road accidents have already started to take their toll in some parts. Because of these re-introduction programs you are now six or seven times more likely to see an otter in your local river than you were just 10 years ago.
The otter is a charismatic animal and is a joy to watch and photograph if you can get close enough. They live for 10-12 years and feed on a variety of fish, crustaceans, occasional frogs and an assortment of other riverside tidbits. As well as inhabiting Britain, the Eurasian Otter is also found across much of Europe, parts of Asia and even North Africa, although it is under threat in much of its range and even extinct in the Netherlands.
The otter is just as happy in salt water as it is in fresh water, often diving down 20 metres or for up to two minutes at a time, although records show that otters can go as deep as sixty or seventy metres and stay under for up to four minutes. They must however have access to fresh water to clean themselves with as the salt water clogs up their fur and inhibits insulation.
Otters live in a burrow in the bank of a waterway called a holt. This is usually only accessible from underwater so is very successful at keeping out uninvited guests. Artificial otter holts are a good way of encouraging breeding among wild otters by providing them with a ready-made safe place to bring up their young.
Otters are generally solitary but come together to breed. The young (1-4 cubs) are born blind in the holt after a 63 day gestation period, they stay in the holt initially and then venture out with their mother, remaining dependent on her for at least a year. This dependency on the Mother being a major reason why populations find it difficult to recover if otters are killed. Once the cubs have left the mother they will take another one to two years before they become sexually mature.
With a bit of luck, continuing conservation and the continuing increase in the quality of the nation’s water, it is hoped that seeing wild otters on the banks of our rivers won’t be the rarity that it is at the moment.