Reproduction

Breeding takes place in the spring.

After 60-70 days the mother will give birth to between 2 and 3 cubs. Young may also be known as whelps and pups.

These cubs suckle milk from their mother for 3 months and remain with her for the first year of life.

For nesting the Eurasian otter will make use of holes in the river bank or cavities among roots, rock piles, wood or debris. These burrows are known as holts.

At birth the young are not naturally inclined to go in the water. Instead at around 16 weeks old the mother will drag the young to water for their first swim. Soon though they love the water and will spend hours playing in it.

Mothers teach their young how to hunt by catching a fish and then releasing it near the cubs.

Sexual maturity is reached between 2 and 3 years old. Females tend to mature later than females.

Behavior

While swimming they are able to close their ears and nose to prevent water entering these. While swimming they can remain underwater for up to 30 seconds. To access the water they slide down the riverbank on their belly.

Outside of the breeding season and while raising young these animals are solitary. Each individual maintains a territory which is marked by their droppings known as spraints. These are placed on rocks, driftwood and debris.

These animals are primarily active by night in most of their range though in a few regions they do come out during the day.

While primarily found in freshwater environments they may swim in saltwater in parts of their range. Once they leave the water they will find freshwater to rinse their fur in.

Eurasian otters can produce a range of vocalizations including calls which convey alarm, greeting or mating. Yelps, screams, whimpers and whistles are also created.

Predators and Threats

Natural predators of the Eurasian otter include birds of prey and crocodiles.

Populations saw significant declines during the second half of the 20th century. These were primarily attributed to the use of pesticides. Once these were banned in 1979 numbers began to increase. Some coastal populations are also victims of oil spills.

Previously these otters were viewed as a threat to the livelihood of fisherman. This led to governments such as the one in Switzerland implementing a bounty for each otter that was killed.

In parts of their range they are still the subject of hunting both for their coat and to be turned in to food.

Otters act as a bioindicator as they require fresh water to survive. When their populations begin to decline it indicates that the environment is unhealthy.

Other threats include entanglement in fishing gear such as nets, drowning and vehicle strikes.

Quick facts

The Eurasian otter is also known as the European otter or the common otter.