Otters are among the best-loved of Britain’s mammals, immortalised in books such as Tarka the Otter, Ring of Bright Water and The Wind in the Willows. Like many other of the UK’s native mammals, such as the Scottish wildcat, otters came off badly in the competition with humans for living space and endured a significant decline – though unlike creatures such as wolves they did not become extinct in the British Isles.
Some Facts About Otters
The breed of otter found in the United Kingdom is the European or common otter (Lutra lutra). Otters are familiar from television wildlife programmes but in fact are rarely seen because of their elusive and secretive natures. They are easily confused with the mink, which is plentiful in parts of the country, but are substantially larger – otters are up to 70cm in length, with the tail adding a further 40cm.
As befits aquatic mammals, otters are physically adapted to life in the water. Their short, thick fur, prized by hunters in the past, has evolved to trap bubbles for insulation and buoyancy and their feet are webbed. They also have the ability to close both ears and nostrils when under water.
At over a metre in length, otters are among the country’s largest carnivores. Their diet is predominantly fish, although they will occasionally take frogs, small water birds, eels and eggs, while those which live along the coast will eat shellfish and crabs. The large quantities of fish which they eat – up to 15% of their body weight daily – makes anglers their enemies (see below).
Otters live near rivers, lakes and coasts, though those with a coastal habitat shouldn’t be confused with the sea otter, a separate species which is not found in the UK. Regardless of where they live, otters need fresh water to maintain the cleanliness and insulating qualities of their fur. They live in dens, known as holts, which are underground in river banks or tree rot systems, though they sometimes sleep above ground.
The Resurgence of the United Kingdom’s Otter Population
European otters were once common from Ireland to Japan. Like many other creatures, however, they are now absent from many areas where they were formerly widespread, including the UK. The decline began in the mid 1950s and within 20 years they were almost absent from England (apart from the south west) and found only in some areas of Ireland, Wales and Scotland (Cardiff University Otter Project).
Historically, otters have survived threats such as hunting (their fur was highly prized) and habitat loss. The key factor in the recent decline seems most likely to be pollution, including organochlorides (OCs) and polychlorinated biphenols (PCBs). As well as affecting water quality (causing a reduction in fish for food) these chemicals accumulated in the marine food chains. The otters ingested them with their food, with the result that breeding levels were affected and population levels fell.
Although there are no readily available figures for otter numbers in the UK, individual surveys and anecdotal evidence do exist. All of these indicate that the otter is very much ‘on the up’ in the UK. In 2003 The Guardian, for example, quoted an estimated figure of 4,000 otters, while in the same year The Independent reported that the animals were living in major cities such as Birmingham, Leeds and Glasgow.
The reasons for the animals’ recovery are varied. They haven’t been subject to reintroduction programmes like some other species such as the beaver and so the recent expansion seems the result of a general, rather than specifically targeted environmental campaign, although they do have legal protection. Key factors seem to have been:
- Increased water quality and improved fish stocks: as fish return to rivers, otters follow
- Habitat management to protect the otters’ living space
- Banning or restricting harmful chemicals such as PCBs.
Although conservationists are delighted with the otters’ recovery, not everyone is keen to see them arriving in their backyard. The animals’ prodigious appetite for fish hasn’t endeared them to anglers, and especially not to the owners of managed fisheries. It is perhaps a mark of the species success that in February 2010, the Angling Trust called for them to be culled after thousands of pounds’ worth of fish was taken from commercially-stocked lakes (The Times).
Where to See Otters in the United Kingdom
Otters may be back living even in the most industrialised areas, but their elusive nature makes them very difficult to see and the dedicated otter-spotter is more likely to find traces of them than catch a glimpse of the otters themselves. Local knowledge might be the best way, through contacting a wildlife organisation. Alternatively, the Forestry Commission website gives suggested locations throughout England, Scotland and Wales.
Sources and Further Information
Dartmoor Otters
UK Biodiversity Action Plan
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