River Otter
North American River Otter Facts
| Size | 22-35 inches (57-90 cm) |
| Speed | 8-11 km/h |
| Weight | 18-25 pounds (8-11 kg) |
| Lifespan | 8-13 years |
| Food | Fish, frogs, crayfish, turtles |
| Predators | Cougars, bears, coyotes, wolves, alligators |
| Distribution | North America |
| Habitat | Rivers, lakes |
| Order | Carnivores |
| Family | Mustelids |
| Scientific name | Lontra canadensis |
| Characteristics | Predator with black and white head; wedge-shaped body |
Main Characteristics
Otters belong to the marten family. They're the only ones who spend most of their time in the water. They have webbed feet, a thick fur and a thin, streamlined body that is perfect for swimming and diving. The best known are the river otter and the sea otter.
Species
There are 14 species of otters, such as the river otter, which live in rivers and lakes, and the sea otter, which lives in the sea. The largest is the giant otter and the smallest is the Asian small-clawed otter.
Distribution and Habitat
Otters are found almost everywhere in the world except Australia and Antarctica. The river otter is the most common otter in the US. Its preferred habitat are rivers and lakes.The most widespread is the Eurasian otter, which lives in Europe, North Africa and Asia.
Life Style
River otters are mainly active at dusk and at night. They live solitary or in pairs and spend most of their time diving for food and eating. They groom their fur several times a day by scratching it with their claws. They also rub against grass, stones or trees. They live both on land and in water.
Anatomy and Appearance
Size and Weight
River otters have a body length of 26-42 inches (66-107 cm). The tail is about 12-20 inches (30-40 cm) long. An average male weighs 25 pounds (11 kg) and an average female 18 pounds (8 kg).
Webbed Feet
River otters have webbed feet to move quickly in the water.
Whiskers
River otters have long whiskers on their mouths. They help them find prey in murky water.
Fat Layer
River otters don't have a blubber layer - unlike other mammals that live in water. Instead, they have thick fur that keeps them warm.
Fur
Otters have two layers of fur: an undercoat and a top coat. The dense undercoat keeps them warm and dry. The top coat consists of long hairs that keep water out. River otters have an average of 390,000 hairs per square inch (60,000 per square centimeter). Sea otters have even more. What about us? A human has up to 150,000 hairs on their head – however, not per square inch, but in total.
River Otter or Sea Otter – What’s the Difference?
Apart from the habitat, river otters and sea otters share many characterstics. They spend a lot of time in the water, have thick fur, webbed feet, a long body and tail, and small ears. However, there are a lot of differences. The river otter is significantly smaller and lighter, has less hair per square inch and feeds on fish, frogs and crayfish. It doesn't sleep in the water either, but instead looks for a safe place on land.
Diet
Otters are carnivores. They have to eat a lot to maintain their body temperature in cold water. River otters mainly eat fish, frogs, crayfish, turtles and small mammals. They need about 2-3 pounds (1-2 kg) of food per day.
Behavior
Playfulness
River otters are very lively animals. They tail chase each other, wrestle and play. They even build slides out of mud and enthusiastically slide over the snow in winter.
Grooming
River otters spend a lot of time every day grooming their fur to keep it waterproof.
Are River Otters Dangerous?
Otters avoid meeting people. However, if they feel cornered or threatened, they can become very aggressive. They're very strong and have sharp claws with which they defend themselves. They can also transmit diseases. As long as you avoid confronting them, there is no need to fear being attacked by them.
Otter Burrow
Location and Structure
River otters dig burrows near the water's edge to rest, sleep and raise their young. The entrance to the burrow is 20 inches (50 cm) below the water surface, as are the tunnels. Only the living chamber is dry because it is above the water surface. It is supplied with oxygen through an air shaft.
What Do Otters Do in a Beaver Lodge?
River otters aren't picky. They also inhabit abandoned animal burrows such as beaver castles.
Senses and Abilities
Swimming
River otters are excellent swimmers. They're known for their agility and speed in the water.
Diving
River otters can stay underwater for up to eight minutes. To prevent water from getting into their ears and nose, they close them beforehand.
Sense of Smell
River otters have an awesome sense of smell. They can probably even smell underwater.
Life Expectancy
In the wild, river otters live 8-13 years.
Enemies and Threats
Natural Enemies
The otter's natural enemies include cougars, brown bears, black bears, polar bears, coyotes, wolves and alligators.
Human Impact
Habitat loss is the greatest threat to otters. Rivers are drained, river courses are changed and forests are cleared to build settlements and agriculture. In addition, water bodies are becoming increasingly polluted by waste and pesticides. The animals are also killed by fishermen - or by their nets.
Importance for the Ecosystem
River otters play a crucial role in maintaining the balance of nature by preventing other animal species from overpopulating and by preying on weak, sick, old, or injured animals. This helps to ensure a healthy ecosystem within their habitat.
Reproduction
River otters can delay the implantation for 9-11 months. After a gestation period of 60 days, they give birth to 3-4 young between March and April. The babies are helpless for the first few weeks and only open their eyes after four weeks. After eight weeks they learn to swim. They then learn to hunt from their mother. They stay with their mother for a total of 12 months.
River Otter Foot Prints
It is quite easy to identify otter footprints in mud or snow. When running, a “chain” of four paw prints is created. Then there is a small gap and then follows the next chain. Sometimes its trail is confused with that of a raccoon. Both have five toes on their front paws and hind paws. However, raccoon prints look more like hands with fingers and they don't run in chains of four either.
Otters as Pets
Otters are funny, lively animals. Many people want to buy them or catch them to keep them as pets. Finally, there are many videos in which YouTubers (especially in Asia) keep an otter as a pet - like a cat or a dog. However, species-appropriate keeping is hardly possible because the animals need a lot of space, a river and several pounds of fish every day. They also pose a danger to people because they bite and scratch. In Germany, you also need an official permit to keep them.
Fun Facts
Name Origin
The animal's name comes from the English word for water.
In German
The German word for river otter is „Fischotter“ (Fisch = fish).
The River Otter Is Related To:
- Badger
- Marten
- Polecat
- Sea Otter
- Weasel
- Wolverine
