The European Otter (Lutra lutra) is a large semi-aquatic mammal in the same family as badgers, pine martins and weasels. They can grow to about 1 – 1.3 metres and weigh between 7 -10kg. They have short limbs, webbed feet and claws, with two layers of fur, a waterproof outer and insulating inner layer.
Otters are territorial animals living along the banks of streams, rivers and lakes. They tend to be solitary except during mating seasons and when raising their cubs. Nursing and raising young lasts for approximately 12- 15 months.
Although they’re particularly good swimmers they cannot hold their breath for long, an average dive will last only 30 seconds. They’re diet consists of mostly fish but they will occasionally catch birds, other small mammals and frogs.
Having otters in a water body is a good indication of water quality, whereas some other species such as Water Voles can survive for periods in polluted water, Otters cannot. The loss of suitable food being one of the many factors.