Range:

Africa, Asia, and parts of North America, Central America, and South America

Habitat:

Oceans, coastlines, freshwater rivers, lakes, and marshes

Champion swimmers

Otters are the only serious swimmers in the weasel family. They spend most of their lives in the water, and they are made for it! Their sleek, streamlined bodies are perfect for diving and swimming. Otters also have long, slightly flattened tails that move sideways to propel them through the water while their back feet act like rudders to steer.

All wet

Almost all otters have webbed feet, some more webbed than others, and they can close off their ears and nose as they swim underwater. They like to swim on their back and sides and can see just as well underwater as they can above. Otters can stay submerged for five to eight minutes, depending on the species, because their heart rate slows, and they use less oxygen. Sea otters are good at floating on the water’s surface, as air trapped in their fur makes them more buoyant. They are much more buoyant than river otters, which have to actively swim to keep afloat.

You can tell otter species apart by the shape and amount of fur on their nose.
Unlike other marine mammals, sea otters do not have a layer of blubber to keep them warm; they rely on warm air trapped in their fur.
Sea otters have the densest fur of any mammal, with about 100,000 hairs in a space about the size of a postage stamp.
Most otter species capture prey with their mouth, but Asian small-clawed otters and sea otters have flexible fingers and grab with their hands.
North American and European river otters have been known to share dens with beavers—but the beavers do all the building,
Otters can close off their ears and nose as they dive and swim underwater.
River otters can stay submerged for up to eight minutes, a relatively long period of time for an air-breathing mammal.
Otters are the only truly amphibious members of the weasel family.
Sea otters often hang out together in large groups called rafts.
The marine otter is also known as the sea cat for its many whiskers.
The name otter is derived from Old English and Indo European root words that also gave rise to the English word for water.
The spotted-necked otter is called “fisi maji,” which means water hyena in Swahili.
Otters are quite flexible and can easily touch their nose to their tail.

Otters were not often kept in zoos before the 1950s. But the San Diego Zoo’s first otters, two male Pacific otters, arrived in 1934. Our otter collection gradually grew to include giant, Asian small-clawed, smooth-coated, and North American river otters. In 1991, we received our first Eurasian otters, a pair from a zoo in Switzerland. Six years later, they surprised us with a pup, the first of its kind born in the United States!

Today, the San Diego Zoo has a Pacific otter in the Children’s Zoo and a Cape clawless otter along Center Street (you can read about her in a blog titled A Knee Makeover for Sweet Otter). We are one of just six zoos in the United States to exhibit spotted-necked otters. You can watch their antics in the Zoo’s Lost Forest, where they live with swamp and spot-nosed monkeys.

It’s hard to determine the wild otter population because of their secretive nature and wide range. There are many studies showing the decline or extinction of otters in certain areas. In most countries, otters are now classified as either threatened or endangered and are under special protection. The North American river otter Lontra canadensis was once in serious trouble because of habitat destruction and trapping, but as a result of reintroduction projects and legal protection, their numbers have increased throughout North America.

There are several factors affecting the decline of river otters. The pollution of rivers and waterways is a major threat. Substances such as organic waste from domestic and industrial sources and pesticides used to control insects are often washed into waterways. Oil spills contaminate an otter’s fur, increasing heat loss, reducing buoyance, and proving toxic when ingested.

Habitat destruction or loss is also a major factor affecting the river otter. Construction of dams leaves lower rivers dry and unsuitable for river otter populations. Deforestation affects river otters through much of South America and Asia. Mining rivers for gravel kills the fish that are the otters’ main food source. Changing river courses for flood prevention and agriculture destroys otter habitat. River otters are also hunted and trapped for their pelts or killed by fishermen who see them as competition. And otters often get trapped and drown in fishing nets.

California or southern sea otters Enhydra lutris nereis were nearly wiped out a century ago, hunted for their thick fur. An international treaty banned otter hunting in 1911, but the species has been slow to recover from the devastation. Some researchers believe pollutants in the water off of California’s coast and the increase of commercial fishing operations have had an effect.

Today, giant otters Pteronura brasiliensis, marine otters Lontra felina, South American river otters Lontra provocax, and hairy-nosed otters Lutra sumatrana are endangered.

You can help!
Want to help otters? Use water-efficient appliances! Water-efficient washing machines and dishwashers, low-flow showerheads, and low-flush toilets can reduce water consumption by 60 to 90 percent. That means more clean water stays in our rivers where river otters live.

You can help us bring otters back from the brink by supporting the San Diego Zoo Global Wildlife Conservancy. Together we can save and protect wildlife around the globe.