A brief species factfile

The European otter has been here for millions of years; it is a member of the Mustelid family, which also includes the badger, mink, weasels, stoats, martens and polecats, and is the only truly semi-aquatic member of the weasel family.

The average otter is 1–1.3 metres in length, and weighs up to 9kg. Their diet consists of roughly 80% fish, but they will prey upon birds, mammals and frogs if fish are in short supply. Their gestation period is 9 weeks and they can breed at any time of the year, although this usually occurs in spring. They have 2 or 3 cubs weighing no more than 40g; these are not born natural swimmers, and very often adults will force their young into the water for their first swimming lesson. Youngsters will open their eyes within 5 weeks. Despite being strong swimmers, otters are unable to hold their breath underwater for long periods and usually dive for no more than 30 seconds at a time.

Otters have an acute sense of smell, hearing and eyesight. Its eyes are placed at the top of the head, so it can remain alert whilst the rest of the body is underwater. They communicate via whistles, twittering noises and spitting sounds, which can be heard at night when it is quiet and still. They live in holes in river banks called holts; a holt will have a few different entrances to protect against flooding, with at least one entrance being above water level. Cubs will stay with and remain dependent upon their parents for over a year. They will start to leave at 14 to 15 months old, and begin breeding at between 17 and 20 months old.

Threats and challenges

Unfortunately, even though the species has made a distinct comeback and is now found often in our rivers, wild otters rarely live beyond 4 years of age.  The oldest recorded otter reached around 19 years of age, but this is exceptional. Reports now state that otters inhabit every county in the UK – great news for the otter! – but our river systems still require extensive habitat management to restore them to a healthy level that can sustain fish stocks and wildlife. This is essential to ensure that the otters reduce predation of stillwater lakes and, of course, so that anglers are able to enjoy their historic and popular pastime and live in harmony with the beautiful otter.

In recent years the otter has encountered new and varied threats, including habitat destruction (road building, new urban development), persecution by fishery owners and gamekeepers (as they are seen as a threat to fish and game birds – which is untrue), and if near the sea, injury and capture in fishing nets. Changes in traditional farming methods also play a part in threatening the otter via the increasing use of pesticides. A recent report by Cardiff University (2013) noted that pesticides and pollutants may also be affecting the otter’s reproductive system. In certain parts of the country road deaths are considerably high – this is something we at the UK Wild Otter Trust want to address by helping with under-road tunnels to help reduce the number of road casualties.