Where Do Otters Live? Holts, Rivers and Coasts

What kind of habitat do otters need?

Every otter needs three things: clean water, plenty of prey such as fish and crayfish, and safe places to rest on land. River otters spend much of their time ashore, grooming, sleeping and raising young, so the banks matter as much as the water. Thick vegetation, tree roots, boulders and fallen logs give them cover.

Otters are good indicators of a healthy river. Because they eat fish and crayfish from the top of the food chain, they are hit hard by pollution, and they disappear when rivers become dirty or fish stocks crash. Where they return, it usually means the water has improved.

What is an otter holt?

An otter’s den is called a holt. It may be a tunnel in a riverbank, a gap among tree roots, a cave in a rock pile or a hollow under fallen trees. Otters rarely dig from scratch. The North American river otter often moves into the old burrows of beavers, muskrats or woodchucks, or even into a beaver lodge, and many dens have an underwater entrance.

In Britain and Ireland, naturalists also use the word couch for an above-ground resting place, such as a flattened bed in reeds or brambles. A single otter uses many holts and couches across its range, choosing one for the day depending on where it has been hunting. Breeding females pick the safest, quietest holts to raise their cubs.

Territories along waterways

River otters do not live in one spot. They patrol long stretches of river, lake shore or coast, and their ranges are measured in kilometers of waterway rather than in area.

Males usually have larger ranges that overlap those of several females. Otters mark their ranges with droppings, called spraint, left on prominent rocks, logs and bridges, plus musky secretions from glands near the tail. These scent posts tell other otters who is around.

Where do North American river otters live?

The North American river otter lives across most of Canada and Alaska and much of the United States, from the Pacific Northwest and the Great Lakes to New England, Florida and the Gulf Coast. It uses rivers, lakes, marshes, swamps, estuaries and rocky sea coasts, and tolerates frozen winters and high mountains. It was wiped out from many central and eastern states but has returned thanks to reintroductions in about 20 states.

Where do Eurasian otters live?

The Eurasian otter has one of the widest ranges of any mammal, from Ireland and Portugal across Europe and Asia east to Korea and the Russian Far East and south to Indonesia, plus parts of North Africa. It lives on rivers, lakes and canals and along rocky coasts, especially in Scotland, Ireland and Norway, where it hunts in the sea but needs fresh water to rinse salt from its fur. After a steep decline in the 20th century it has recovered across much of western Europe. Learn more in Are there otters in the UK?.

The world’s 13 otter species and where they live

The IUCN Otter Specialist Group recognizes 13 living otter species.

Africa and Asia have the most otter species, with four or five each. The Japanese river otter, once found in Japan, was declared extinct in 2012.

Do otters live in the sea?

Two species truly belong to the ocean. The sea otter lives almost its whole life in the water, floating on its back in kelp forests and coastal bays. The marine otter of Peru and Chile lives on wave-beaten rocky shores and hunts in the surf.

Several river otters also use the sea. Coastal Eurasian otters in Scotland and Norway and North American river otters in Alaska and British Columbia hunt in salt water but come ashore to rest and to rinse their fur in fresh water. See sea otter vs river otter for how to tell them apart.