One of our top predators, the elusive European Otter feeds mainly on fish, particularly eels and salmonids, but will eat amphibians and crustaceans too.

These semi-aquatic mammals are seldom seen because they're primarily nocturnal. During the day they sleep in 'holts' hidden away in vegetation at the water-side. They have their cubs in these underground burrows, and their young are normally in the water, being taught to swim by Mum, by 10 weeks of age.

Otters are well-suited to a life on the water; they have dense fur to keep them warm, webbed feet to aid swimming and they can close their ears and nose when underwater. They have large territories; a single individual spotted on the Montgomery Canal - a stronghold for these animals, where they feed - is also likely to make use of the nearby River Severn, as well as many smaller watercourses.

They require clean rivers, with abundant food and plenty of vegetation to hide their secluded holts '- this is why otter populations are under threat, with river pollution and habitat loss playing major roles in their plummeting numbers.