Otter (Lutra lutra)

What do otters look like?

Thick brown fur covers a long slender body, a thick tail and short legs. The chest and belly fur is often paler in colour. They have a broad nose and small ears, with eyes high on the head to enable better vision when they are mostly submerged in the water.

The long muscular tail and webbed feet make otters strong swimmers while sensitive whiskers and claws help them to detect and catch their prey.

One of our largest mustelids, they weigh in at 7-11kg and measure 94cm-155cm from nose to tail. On average, males are larger than females.

What do otters eat?

Otters are carnivores that feed mostly on fish like trout, carp and eels. They happily eat amphibians, crustaceans and waterbirds like moorhens and coots too. 

Sometimes they will look for food on land, selecting birds, eggs, insects and small mammals to satisfy their appetite - otters will usually eat more than 2lbs of food a day.

Where do otters live?

Otters can be found throughout the UK, though with lower densities in England which was worst affected by polluted waters. Otter hotspots include the west coast of Wales and South West England. 

They will live wherever there is clean freshwater with plenty of food and secluded areas of vegetation to rest and raise young. Rivers, canals and lakes are ideal, and coastlines too if there's a freshwater source nearby.

Nests known as holts are usually made in natural cavities in riverbanks, tree roots, shrubby thickets or rocky crevices. Lined with grasses, ferns, reeds and leaves, they have multiple entrances, some of which may be underwater. Some holts have more than one chamber too, which the otter may connect by digging a system of tunnels, including one to use as a latrine.

With large territories, otters use a number of resting places in areas of overgrown vegetation as well as their holt. Some they return to frequently and some only occasionally.

Signs and spotting tips

As otters are most active at night, dawn and dusk are good times to look out for them. Follow our spotting tips for the best chance of tracking them down.

• Tracks: look for otter tracks in mud and sand close to the water. Around 40-80mm across, they have five toes (though may only show four). Their claw marks can't usually be seen, but you might be able to see the webbing.
• Spraint: otter droppings, known as spraints, are a greenish, black-grey colour and full of evidence of their diet: bones, shells, feathers and fur. They smell sweet and musky, like jasmine tea or laurel flowers. Left on rocks and logs close to the water, they are a method of communication with other otters. 
• Water activity: spot otters from a distance in the water by a stream of bubbles as they dive and the V-shaped wake behind them when they swim. On the water's surface, their head and back are barely visible - but you might just catch a glimpse of their powerful tail as they dive below in search of food.

Threats and conservation

The return of the otter across the UK is a conservation success story. By the 1950s, the species was on the brink of extinction due to hunting, habitat destruction and chemicals leaching into watercourses. But the 1980s was a turning point. Otters were given their current protection under law, the chemicals were later banned so improving water quality, and an ongoing programme of releases increased numbers towards the more stable populations of today. 

The otter has no natural predators in the UK, but pollution and road traffic accidents remain a threat.