

Activities
European Otter
Lutra lutra

Photo Copyright Helen Taylor
Appearance
Otters, including their tails, are about 1m in length. They have a streamlined body with a small head, small ears and a powerful tail which it moves like a rudder to help direction whilst swimming in water.
The Otter’s coat is rich brown. The coat is made up of two layers: an outer layer of long coarse hairs, and an inner layer of very thick fine hairs which keep the water out. When the Otter dives the under-layer traps air, this helps to keep the Otter warm. If you watch an Otter in water you will see a trail of tiny bubbles.
Habitat and Distribution
Otters are found in both sea and fresh waters. They like to live along undisturbed river banks.
They are found throughout Britain and Ireland. However Otter numbers have reduced during the 20th century due to habitat loss, pollution and possibly hunting. Otters have recently returned to the Midlands after having disappeared from the region. This is thought to be due to improvements of water quality and habitats.
Home
Otters live in a holt. Holts are dug into a river bank with a chamber lined with grass and plants and one or more entrances, possibly one entrance from underwater.
Otters usually travel on their own and usually have a territory of a 15 mile stretch along a river.
Family
Otters find a mate at any time of the year. Several male Otters may fight over a female. The successful male Otter must then attract the female, he does this by whistling to her in the dark, an interested female will whistle back. By whistling they will be able to find each other to mate.
The couple stay together for a few weeks, but the female will drive the male away before the cubs are born. The pregnancy lasts 62 days.
Normally 2-3 young cubs are born, they are born blind and toothless and are about the size of a rat. The cubs stay with their mother for up to a year. The cubs’ coat is not waterproof until about the age of 4 months. Even then they are often reluctant swimmers, the mother will often have to push or pick her young up and dip them into the water before they take to river life.
Otter keep in contact with each other though smelly messages. They leave droppings and a smelly jelly around their territory. Their droppings (called spraints) are often left on a prominent rock for other Otters to find. The spraints are dark in colour and have a distinctive musky smell.
Otters enjoy playing. They often play either on their own or with others, sliding down into river banks or tossing a pebble between their paws.
Feeding Habits
Otters eat fish, eels, amphibians (frogs and toads), and crustaceans (mussels and other shellfish). They will also eat small mammals and birds.
Just before diving Otters take a deep breath allowing them to swim underwater for up to 4 minutes. The Otter can hear very little under water and so uses it’s good eyesight to find food in water. Otters also have whiskers to help detect fish in muddy waters.
Enemies
The Otter has no natural predators. However the polluting of water ways and habitats by humans has lead to a decline in the Otter population.
Activities
The Otters coat is kept waterproof through natural oils. Detergents polluting water has affected Otter numbers by affecting their natural waterproofing. Once the Otter’s coat is damaged the Otter gets too cold and wet and dies. Investigate the effect of detergents: add a tablespoon of oil to a cup of water, even when shaken the oil and water do not mix. Now add some detergent in the form of washing up liquid, what happens to the oil and water when shaken up?
For more information about Otters:
http://www.cornwallwildlifetrust.org.uk/nature/otters/
More Activities
Glossary
Predators:
Animals which hunt other animals.
Habitat: A place where an animal lives
Territory: The area an animal lives in including the area it uses to find food.
Mate: A male and a female find each other to mate and have babies.
Back to the top of Otters page