93 Fun Facts About Otter

Otters belong to which animal family, also known for weasels and badgers?

Mustelidae is the weasel family, and it used to hold the skunks as well, until genetic evidence moved them into a family of their own, Mephitidae.

In the Harry Potter books, whose Patronus takes the shape of an otter?

Hermione Granger casts a silver otter because J.K. Rowling gave the character her own favourite animal.

In southern Bangladesh, fishermen have bred smooth-coated otters for generations to do what job?

Herd fish into nets is the job: smooth-coated otters naturally hunt in groups that drive shoals together, and the fishermen breed and train them to use that instinct.

Otters hunting in dark or murky rivers track their prey with which sensitive feature?

Whiskers do the tracking: the long, stiff hairs pick up the pressure changes a moving fish makes, so an otter can hunt in cloudy water or in the dark.

What is a common term for an otter's den or burrow?

A holt is the otter's den, fitted into almost any cavity near the bank, from tangled tree roots to piles of boulders, then lined with moss and grass.

Sea otter fur is the densest of any animal, with roughly how many hairs per square inch?

1 million hairs per square inch, about ten times what grows on a whole human head, stand in for blubber: the sea otter has none, so its coat traps a layer of warming air.

Sea otters, among the few tool-using mammals, most often use what to crack open shellfish?

Rocks serve as both hammer and anvil: a sea otter rests a stone on its chest and pounds a clam or mussel against it until the shell gives way.

What are resting groups of ten to a hundred sea otters, all of one sex, called?

Rafts form only for resting: each sea otter dives for its food alone, then floats back to join a group of its own sex.

The giant otter, the longest otter of all, lives mainly along which great river?

Amazon waters are its stronghold, and unlike most of the weasel family the giant otter is highly social, living and hunting in close-knit family groups.

The Asian small-clawed otter, the smallest of all, uses nimble paws to dig out which main prey?

Crabs are its staple, dug out by touch from mud and sand, and the ones it eats are counted a crop pest in rice paddies.

'Otter', from Old English 'otor', shares a Proto-Indo-European root with which everyday English word?

Water and 'otter' grew from the same ancient root, so the animal's name simply means 'water creature'; the Greek hydra, a water snake, is another cousin.

River otters cross snow, ice and muddy banks with which playful move, also a quick way to travel?

Sliding is more than fun: the play is thought to strengthen family bonds and let young otters rehearse hunting moves, and on ice it is simply an efficient way to get about.

In Norse myth, which god killed the dwarf Ótr while he was in otter form?

Loki killed Ótr by mistake, not knowing the otter was a shapeshifting dwarf, and had to pay his father Hreidmar enough gold to cover the pelt, a hoard that came with a curse.

In Japanese folklore the otter, or kawauso, tricks humans in the same way as which two other shapeshifting animals?

Foxes and tanuki are the otter's fellow tricksters: kawauso tales have them snuffing out travellers' lanterns and turning into beautiful women to fool young men.

Which religion classes the otter as a clean animal whose killing is a grave sin?

In Zoroastrianism the otter is a clean creature of Ahura Mazda; the Vendidad devotes a chapter to the heavy penalties for killing a 'water dog', its word for the otter.

In 2012 Japan's Environment Ministry declared the Japanese otter what?

Extinct was the verdict, 33 years after one was last officially recorded; an otter filmed on Tsushima Island in 2017 raised hopes, but its DNA turned out to be the Eurasian otter's.

The 1911 treaty that halted the sea otter hunt was written mainly to protect which other animal?

Fur seals gave the 1911 treaty its name, but it also ended a hunt that had cut sea otters from at least 150,000 to as few as 1,000 to 2,000 animals.

Sea otters are a classic keystone species because their appetite keeps which animals in check?

Sea urchins, left unchecked, multiply and graze away the underwater forests that shelter fish and other sea life, so one hungry predator holds the whole habitat together.

Where does a diving sea otter stash the food it collects?

In a loose skin pouch under each foreleg, usually the left, a sea otter can carry several prey items up at once, leaving its paws free to keep gathering.

To avoid drifting out to sea while resting, sea otters wrap themselves in what?

Kelp is the anchor, and mothers use it too: before diving for food, a sea otter may leave her pup wrapped in the fronds so it cannot float away.

Gavin Maxwell's 1960 bestseller about living with otters on the Scottish coast is titled what?

Ring of Bright Water takes its title from a poem by Maxwell's friend Kathleen Raine, and its success led to a 1969 film.

Gavin Maxwell's otter Mijbil, brought home from Iraq's marshes, was found by London zoologists to be what?

Mijbil proved to be a previously unknown subspecies of the smooth-coated otter, named Lutrogale perspicillata maxwelli, or Maxwell's otter, in his honour.

Henry Williamson's 1927 novel Tarka the Otter is set in which county?

Devon's Taw and Torridge rivers are Tarka's home, and the county council later laid out the Tarka Trail along the route the otter takes in the book.

According to Henry Williamson, the name 'Tarka' means what?

Wandering as Water was Williamson's own gloss on the name, and the prize money the book won bought the hilltop field where he built his writing hut.

Monterey Bay Aquarium readies orphaned sea otter pups for the wild by pairing each with what?

A surrogate otter mother, a female that cannot be released herself, teaches the pup to groom and forage, while human carers keep their distance so it stays wild.

The marine otter of Chile and Peru is known in Spanish by what nickname?

Gato marino ('sea cat') echoes its scientific name, Lontra felina; it favours rocky coasts pounded by heavy seas, where it shelters and dens in caves.

The giant otter's Brazilian nickname onça-d'água likens it to which animal?

Jaguar is the comparison: onça-d'água means 'water jaguar', a fitting name for a top predator that hunts in family groups and is the noisiest of all the otters.

A family group of giant otters is typically led by whom?

A lifelong breeding pair heads the group, and the rest are mostly their grown offspring, who stay on and help catch fish for each year's new pups.

At which CITES level has the Asian small-clawed otter been listed since August 2019?

CITES CoP18 in Geneva voted in August 2019 to move the Asian small-clawed otter from Appendix II to Appendix I, banning international commercial trade in the species.

Otters live wild on every continent except Antarctica and which other?

Australia has no otters of its own, although they live as close as Indonesia; Antarctica is the only other continent without them.

The sea otter's genus name Enhydra comes from Ancient Greek words meaning what?

In the water is the literal meaning, and it fits: the sea otter can live its whole life without ever leaving the sea.

A sea otter dives to the seabed for food, but where does it always eat its catch?

Afloat on its back, a sea otter uses its chest as a table, and it eats about a quarter of its body weight every day to fuel the metabolism that keeps it warm.

Which 1989 disaster killed thousands of sea otters in Alaska's Prince William Sound?

The Exxon Valdez oil spill coated more than a thousand otters within days; oil ruins the fur's insulation, and an estimated 2,800 died.

Which Water-type starter Pokémon from the Unova region is classed as the Sea Otter Pokémon?

Oshawott fights with its scalchop, a shell it carries on its belly and wields like a knife, much as a real sea otter keeps its dinner on its chest.

A steep decline in sea otters around Alaska's Aleutian Islands is suspected to be the work of which predator?

Killer whales are the suspects, though the case is still debated: the losses fit a rise in predation, yet very few attacks have ever been seen.

In 2021 a British man was ambushed by about 20 otters in the botanic gardens of which city?

Singapore's Botanic Gardens were the scene in November 2021; the man believed the otters had mistaken him for a runner who had dashed past them moments earlier.

North American river otters can give birth up to a year after mating thanks to which reproductive trick?

Delayed implantation keeps the fertilised egg on hold for months before it settles in the womb, so a pregnancy that really takes two months can end a year after mating.

Africa's spotted-necked otter hunts fish mainly by which sense?

Sight guides its short dives after fish, which is why it keeps to clear water and why murky, polluted lakes are such a threat.

The naturalist who first described the sea otter also gave his name to which animal, wiped out by hunters within 30 years?

Steller's sea cow, a huge, slow-moving relative of the manatee, was so easy to catch that the last one was gone within 27 years of its discovery.

As of 2025, which US Pacific state has no resident sea otters, after a 1970s release there failed?

Oregon's sea otters were hunted out by the early 1900s, and the animals brought from the Aleutians in 1970 and 1971 faded away within a decade; only the odd stray has turned up since.

A 2007 viral video of two sea otters holding paws was filmed where?

Vancouver Aquarium was home to both otters: Nyac, the paler one, had been rescued as a pup after an Alaskan disaster in 1989 and lived there until she died at about 20.

Which streamer's birthday streams for Rosa the sea otter had raised over a million dollars for Monterey Bay Aquarium by 2024?

DougDoug started the charity streams for Rosa's 20th birthday and kept them going every year; after she died in June 2024, that year's stream was held in her memory.

The sea otter was formerly sometimes referred to as the 'sea' what?

Beaver was the comparison: 'sea beaver' is an old name for the sea otter, whose coat, the densest of any mammal, made it the great prize of the North Pacific fur trade.

Georg Steller’s crew, shipwrecked in 1741, spent the winter hunting sea otters where?

Bering Island, in the Commander Islands, is where the St. Peter was wrecked and Bering himself died; the survivors built a boat from the wreckage and sailed home in 1742 with a cargo of otter furs.

In 1799, Tsar Paul I consolidated rival fur hunters into which chartered monopoly?

The Russian-American Company's 1799 charter gave it a monopoly on trade in Russian America, a decree meant to raise the state's profits and rein in unruly frontier fur hunters.

In 1812 the Russians founded which northern California settlement as their southern headquarters?

Fort Ross was founded by Ivan Kuskov, who ran it until 1821, yet within a few years its sea otter catch was failing and the colony leaned ever more on farming.

California’s sea otters all descend from about 50 animals found in 1938 near which landmark?

Bixby Creek Bridge on the Big Sur coast overlooks the spot where a couple testing a telescope found otters that California believed were extinct, and sightseers soon followed.

Most of the 140 sea otters moved to California's San Nicolas Island in the late 1980s soon did what?

Swam back home is what most did, to the biologists' surprise; the island was meant to hold a back-up colony in case disaster struck the mainland otters.

Which parasite, spread via cat feces in urban runoff, is a major killer of California sea otters?

Toxoplasma gondii can complete its life cycle only inside cats, so every infected otter traces back to cat droppings washed or flushed into the sea.

In California, which predator kills many sea otters with its bite but does not eat them?

Great white sharks leave bitten sea otters uneaten, since they lack the fat a shark is after, yet the bites kill so many that the otters' range has stopped spreading along the coast.

Unlike a dolphin, a sea otter catches fish with what, rather than its teeth?

Its forepaws do the catching, and the rest of the kitchen work too: the same nimble paws twist and pull the prey apart before it is eaten.

California fishermen long blamed sea otters for the decline of which prized shellfish?

Abalone divers blamed the otters, yet the commercial fishery in southern California closed in 1997 because of overfishing, years before otters returned to those waters in any number.

The cry of a sea otter pup is often compared to the call of which bird?

Gull-like cries are a pup's call to its mother, who must leave it floating alone at the surface whenever she dives for food.

Mikio Igarashi's long-running manga starring a sea otter is titled what?

Bonobono has followed its young sea otter hero since 1986, and the strip's success has spun off two films, television anime and even a PlayStation game.

Japan's only confirmed wild sea otter population lives off which island?

Hokkaido's cold eastern coast is the only place: sea otters were hunted out of Japan a century ago, reappeared there in the 1980s and now breed around Nemuro and Kiritappu.

Unlike most marine mammals, the sea otter tops up its fluids by doing what?

Drinking seawater is safe for a sea otter because its unusually large kidneys can strip out the salt and get rid of it in very concentrated urine.

Otter 841, who stole surfboards from surfers in 2023, operated off which California city?

Santa Cruz surfers met Otter 841 in the summer of 2023; born in captivity and released into the wild, she slipped every attempt to catch her that summer.

The North American river otter's scientific species name refers to which country?

Canada is in the name, Lontra canadensis, yet the otter is just as much at home across most of the United States and even reaches the north of Mexico.

What is the transparent inner eyelid that protects a river otter's eyes while swimming called?

The nictitating membrane, a transparent third eyelid, sweeps across the eye to protect it and lets the otter see underwater; its ears and nostrils also close when it dives.

In 2012 a river otter nicknamed Sutro Sam drew crowds after moving into a ruined bathhouse in which city?

San Francisco had not seen a river otter in decades when Sutro Sam settled in the flooded ruins of the Sutro Baths, and so many people came that park staff had to warn them off.

After fish, what is the second-most important prey for North American river otters?

Crayfish come second only to fish for river otters, whose very high metabolism forces them to eat often and in quantity.

Which is the only Canadian province where the river otter was wiped out province-wide?

Prince Edward Island is the only Canadian province where the river otter was extirpated entirely; the species persisted across the other nine provinces and the territories.

River otters leave musky scent messages for one another from glands found where on the body?

At the base of the tail sit a pair of glands with a strong, musky smell, and the marks they leave tell other otters who is about, whose patch it is and who is ready to mate.

A 2011 review of otter attacks on humans since 1875 found they were most frequent in which US state?

Florida accounted for 38% of the cases, and the authors' suggested reason is simple: a surge of building has pushed people into the river otter's home waters.

The giant otter's genus name Pteronura comes from Greek words meaning what?

Wing tail, from the Greek pteron and oura, describes the broad, flattened tail that helps drive the giant otter through the river.

Individual giant otters can be identified from birth by unique pale markings on which body part?

Each giant otter carries a unique cream or white throat patch from birth, letting researchers tell family members apart without tagging.

Besides humans, which animal has been recorded preying on giant otters in Peru?

Black caiman are among the few animals reported to take giant otters; adults in a family group have no serious natural enemies, so it is stray cubs and lone otters that are at risk.

Unlike many otters, the giant otter is active only at which time?

By day is when giant otters fish, play and patrol, and since they are also loud and live in groups, they are among the easiest otters to watch in the wild.

In Spanish-speaking South America the giant otter is known as the river what?

Wolf is the word: lobo de río, 'river wolf', suits an otter that hunts in noisy family packs.

The Achuar people regard giant otters as a form of the tsunki, which are what?

The Achuar see giant otters as a form of the tsunki, water spirits of the rivers whom the Achuar and neighbouring Shuar also regard as the first shamans.

In 2021 a wild giant otter was spotted in which Argentine national park?

Impenetrable National Park's Bermejo River is where a conservationist out kayaking met the otter by chance; the species had not been recorded anywhere in Argentina since the 1980s.

What is the name for the faeces a Eurasian otter uses to mark its territory?

Spraints are packed with fish bones and scales, yet to many noses they smell sweet, rather like jasmine tea; otters leave them in prominent spots as messages to one another.

In Andalusia, Eurasian otters have taken to using artificial lakes on what kind of site?

Golf courses offer what an otter needs in a dry region: ponds of fresh water, which even sea-going otters must visit to wash the salt out of their fur.

In August 2011 otters were declared to have returned to every county of which country?

England's Environment Agency could announce the full return once two otters turned up in Kent; the animals had earlier vanished from everywhere but the West Country and parts of the north.

The Eurasian otter's late-20th-century crash was driven mainly by which kind of pollution?

PCBs and farm pesticides poisoned the otters and thinned out the fish they ate; curbs on the worst chemicals, cleaner rivers and legal protection opened the way to their recovery.

To open shellfish without crushing them, captive Asian small-clawed otters were seen doing what?

Leaving them in the sun was the trick: captive Asian small-clawed otters left molluscs in the sun until the warmth made the shells gape open.

Asian small-clawed otters in zoos are well known for doing what with pebbles?

Juggling them is a favourite game, though perhaps not just for fun: two studies of zoo otters found they juggle most when they are hungry.

Small-clawed otters smuggled to Japan in the late 2010s were mostly sold as what?

Exotic pets were the draw: a boom in keeping otters at home in Japan fed the smuggling.

Smooth-coated otters in Kuala Selangor were seen hunting in what formation across a creek?

The otters formed a V-shaped line across the creek, with the largest animals in the middle, driving panicked fish ahead of them before grabbing them with their snouts.

In which children's classic does Otter's young son Portly go missing, sparking a night-time search?

The Wind in the Willows sends Rat and Mole out by boat to look for Portly, and at dawn they find him asleep at the feet of the god Pan.

Which Southeast Asian otter, once feared extinct, was rediscovered with the help of camera traps?

Hairy-nosed otters, named for the fur that covers the nose pad, have since turned up from Vietnam to Borneo, though they remain among the rarest otters anywhere.

The spotted-necked otter is common in which great African lake?

Lake Victoria's otters now share it with the introduced Nile perch, a fish too big and fast for them to catch, which is thought to be crowding out the smaller species they eat.

Which versatile South American otter turns up everywhere from sewage works to glacial Andean lakes?

The Neotropical otter was hunted so heavily for its pelt from the 1950s to the 1970s that it vanished from parts of its range; it is now protected by law in many of the countries where it lives.

South Africa's Otter Trail, named for the African clawless otter, runs through which national park?

Tsitsikamma's rugged shore carries the five-day trail from Storms River Mouth to Nature's Valley, and the Cape clawless otters it is named for are protected along the whole route.

In Gabon, a myth holds that Congo clawless otters can do what when caught with a spear?

Gabonese lore says the Congo clawless otter can give electric shocks when speared, a reputation that keeps it off the bushmeat menu there, unlike in Congo and Cameroon.

An otter fetching a fish for its master appears on which famous 1539 map of Scandinavia?

The Carta marina, drawn by Olaus Magnus, shows a real practice: tame otters were trained to fetch fish for their owners in much of Europe, from Scotland to Poland.

Which 1653 book on angling by Izaak Walton tells of a tame otter taught to catch fish?

The Compleat Angler has a huntsman kill a mother otter and her young, until the angler begs one cub to tame, citing a Leicestershire gentleman whose otter caught fish for him.

After otter hunting stopped in 1978, some otterhound packs turned to which invasive animal?

American mink, fur-farm animals gone wild on the same rivers, gave the hounds a new quarry once the otter became a protected species.

Which bone did British otter hunters take as a trophy and wear as a tie-pin?

The baculum, or penis bone, was the prized trophy; hunters also cut a notch in their poles for every otter killed.

The little-known Congo clawless otter of Central Africa's rainforests is thought to spend most of its time where?

On land is where this otter does most of its foraging, using its fingers to dig earthworms and frogs out of muddy banks; it is the least studied otter in Africa.

According to the Muromachi-era Kagakushū dictionary, an otter that grows old turns into what?

Kappa, the water goblin of Japan's rivers, was once thought to be what an ageing otter became, and in parts of the country otters were simply counted as a kind of kappa.

Who directed the 1977 TV special Emmet Otter's Jug-Band Christmas?

Jim Henson directed and produced the special, in which Emmet and his widowed Ma each secretly enter a talent contest to win the money for the other's Christmas present.

Who wrote the original songs for Emmet Otter's Jug-Band Christmas?

Paul Williams gave Emmet's band and Ma contest songs that fit together as one; both acts lose the talent show, but the combined number lands them paying work on the walk home.