16 Entertaining and Enlightening Facts About Otters

These endearing water-dwelling mammals are intelligent, vocal, and have a distinct scent.

1. OUT OF THE 13 KNOWN OTTER SPECIES, NEARLY ALL ARE EXPERIENCING POPULATION DECLINES.

The North American River Otter is the sole otter species currently thriving. The International Union for Conservation of Nature (IUCN) has identified the remaining 12 species as having declining populations, with five already classified as endangered. Sea otters along the Californian and Alaskan coasts, for instance, face threats from "environmental pollutants and disease agents." Similarly, South America's marine otters are dwindling due to poaching and ecological challenges.

2. IN ZOROASTRIAN BELIEFS, OTTERS WERE CONSIDERED ALMOST SACRED ANIMALS.

In this ancient religion, otters were revered as the guardians of rivers and seas, often referred to as the dogs of these waters. Strict laws prohibited their killing, as they were believed to maintain water purity by consuming deceased animals that could otherwise pollute the water. Zoroastrians also conducted special rituals for otters that were found dead in nature.

3. OTTER DROPPINGS ARE HIGHLY UNIQUE AND HAVE A SPECIAL NAME.

Otters communicate through their feces, known as spraint, which plays a crucial role in their social interactions. They maintain cleanliness by using specific areas as communal toilets. The scent of spraint can range widely, sometimes compared to the aroma of jasmine tea. Each otter's spraint has a unique composition, allowing them to recognize one another. Researchers believe otters can discern details like gender, age, and reproductive status from the scent. Given their efficient metabolisms, otters consume up to 15% of their body weight daily, resulting in a significant amount of spraint.

4. OTTER MOTHERS ARE INCREDIBLY OPEN TO ADOPTING ORPHANED PUPS.

In 2001, a female otter at the Monterey Bay Aquarium delivered a stillborn pup on the same day an abandoned pup was found nearby. Previously, the staff attempted to raise pups themselves, but these otters grew too attached to humans for successful reintroduction to the wild. To solve this, they introduced the orphaned pup to the female otter, who instantly embraced her maternal role. The aquarium now follows a method where pups are hand-reared for the initial six to eight weeks—primarily for bottle-feeding—before being placed with female otters for further care. By six months, these pups are released into the wild, often with excellent outcomes.

5. OTTERS POSSESS THE DENSEST FUR AMONG ALL MAMMALS ON EARTH.

Otters boast up to one million hairs per square inch, featuring a dual-layer system: a dense undercoat and longer visible hairs. These layers trap air close to the skin, ensuring the otters stay dry, warm, and buoyant. Interestingly, otter pups have so much trapped air that they are unable to dive underwater, even if they attempt to.

6. AN OTTER'S SKILL OFTEN DEPENDS ON THE TOOLS IT USES.

Otters enjoy feasting on shelled creatures, such as clams, but lack the strength to open them unaided. As a result, they rely heavily on tools, frequently using rocks to break into their meals. While foraging underwater, they often tuck a rock into the loose skin under their arms for future use.

7. OTTERS HOLD SIGNIFICANCE IN NATIVE AMERICAN CULTURES, THOUGH THEIR ROLES VARY.

Some tribes regard otters as symbols of good fortune, representing traits like "loyalty and honesty." However, others, especially in regions of present-day Canada and Alaska, viewed river otters with fear and reverence, associating them with spirits of the dead and drowning. Certain cultures even prohibited consuming otters and were deeply troubled when European settlers began hunting them for their pelts.

8. GIANT OTTERS ARE HIGHLY VOCAL CREATURES.

A 2014 study revealed that giant otters produce 22 distinct sounds for various situations. Additionally, pups have 11 unique calls, often mixed with "infant babbling." Notable among these calls are a "hum gradation" used to signal direction changes and a sharp "Hah!" to alert others of nearby threats.

9. OTTERS AND HUMANS CAN WORK TOGETHER IN UNIQUE WAYS.

In Bangladesh, otters assist fishermen by increasing their catch. For generations, fishermen have trained otters to herd fish into nets, making the process more efficient.

10. DRONES COULD REVOLUTIONIZE HOW SCIENTISTS STUDY OTTERS IN THEIR NATURAL HABITATS.

Observing otters in their natural habitat is challenging. Traditionally, researchers relied on shore-based telescopes to monitor otters at sea. However, otters alter their behavior when humans are close, and using telescopes from boats is difficult in rough waters. Now, scientists are employing unmanned drones equipped with cameras to capture aerial views of otters, allowing for easier observation of their diving and daily activities.

11. SPOTTED A GROUP OF OTTERS? THAT'S CALLED A ROMP OR A BEVY.

Alternatively, they can be called a family or a raft. Otter groups have several unique names, each specific to their setting. Typically, a group of otters on land is referred to as a romp, while those in the water are known as a raft.

12. OTTERS LOVE TO PLAY, AND BUILDING SLIDES IS ONE OF THEIR FAVORITE ACTIVITIES.

Otter families typically consist of mothers and their pups, who spend the majority of their time eating or resting. However, during their free moments, otters enjoy playing and often create slides along riverbanks for fun.

13. CALIFORNIA SEA OTTERS ORGANIZE THEMSELVES INTO DIETARY GROUPS.

Once believed to be extinct in the region, southern sea otters—also called California sea otters—have been gradually recovering in recent years. With their population still low, researchers have closely monitored them, uncovering a unique social system. These otters, which must consume 25 to 35 percent of their body weight daily to sustain their metabolism and stay warm in cold waters, are divided into three "dietary guilds": deep divers that feast on abalone, urchins, and Dungeness crab; medium divers that eat clams, worms, and smaller shellfish; and shallow-water otters that feed on black snails.

14. A ZOOLOGIST STRANDED AFTER A SHIPWRECK WAS THE FIRST TO DOCUMENT SEA OTTERS SCIENTIFICALLY.

German zoologist and botanist Georg Wilhelm Steller was the first to provide scientific descriptions of many new animals during the 1741 Russian exploratory voyage. After the St. Peter shipwrecked on what is now Bering Island, Steller and his crew endured a harsh winter. During this time, he carefully recorded numerous species. While some, like the sea cow he described, were hunted to extinction, the charming otter was one of his earliest findings.

15. BABY OTTERS FLOAT EASILY, BUT THEY CAN'T SWIM INDEPENDENTLY.

Mothers often secure their pups in kelp to prevent them from drifting while they hunt. Alternatively, they might use their resourcefulness to create a temporary "playpen" for their young.

16. NOT ALL OTTER BEHAVIORS ARE CUTE.

Similar to many animals, otters occasionally exhibit behaviors that humans might find morally questionable. While they are often seen as endearing, their mating practices can be particularly disturbing.

Male otters employ aggressive mating tactics, often biting the female's face to prevent her from escaping, which can result in severe injuries. Tragically, female otters sometimes die from these encounters, either due to drowning or infections from their wounds. Male otters have also been observed forcing themselves on other species, such as baby seals [PDF]. This behavior persists even after the seals die, with males guarding and continuing to engage with the corpses for up to a week.

Researchers suggest that these unusual mating habits may stem from a gender imbalance. In Monterey Bay, California, where male otters outnumber females, scientists noted instances of otters attempting to mate with deceased seal pups. This behavior, termed "misdirected sexual activity," is more common among transient males without established territories or access to female otters. In the absence of suitable mates, these males redirect their instincts toward seals, highlighting the harsh realities of nature.