Interesting Facts on Otters

Otters have a reputation for being cute but are in fact fierce hunters. They are closely related to weasels, polecats and badgers and evolved about 30 million years ago. There are 13 species living around the world in both fresh- and saltwater habitats. Otters have been heavily hunted all over the world for their fur and are also threatened in many places because overfishing has depleted their natural sources of food.

  1. Description

    • Otters are elongated mammals with short limbs and small heads. All have long, muscular tails except for the sea otter (Enhydra lutris), which has a short tail. Otters have sharp teeth and webbed feet and most have sharp claws. They have short, brown fur with a dense undercoat that traps a layer of air and provides insulation. Sea otters have the densest fur in the animal kingdom. The giant otter (Pteronura brasiliensis) from the Amazon and Orinoco rivers is the largest species and can grow to seven feet long and weigh 100 pounds. The smallest species, which lives from India to China, is the Asian small clawed otter (Aonyx cinerea). It can grow up to three feet long, including the tail, and weigh up to 11 pounds, according to the International Otter Survival Fund.

    Range

    • Otters are found on every continent except for Antarctica and Australia. There are two species found in North America, four in South America, four in Africa and three in Asia. The Eurasian otter (Lutra lutra) is found in Europe, Africa and Asia and is Europe's only otter species, while the sea otter lives in both North America and Russia.

    Habitat

    • Apart from the sea otter in North America and the marine otter (Lontra felina) from the west coast of South America, otters frequent fresh water lakes as well as rivers and estuaries. The sea otter and marine otter are completely marine and the Eurasian otter will live and feed mainly in the sea, especially in Scotland. The sea otter is the most aquatic of all the otters and rarely comes on to land at all.

    Behaviour

    • Otters are carnivorous and feed on a wide range of animals including fish, crustaceans, mollusks and even other mammals. They are active predators and catch most of their food underwater. Some species feed during the day while others are completely nocturnal. Otters are playful and some species, especially the giant otter, are highly vocal and communicate with squeaks and growls. Giant otters live in family groups up to 20 strong, while other species are solitary. All species care for their young until they are fully grown.

    Conservation

    • Otters have been extensively hunted for their dense fur and several species are now considered endangered. There may be only 5,000 giant otters remaining in the whole Amazon basin. The marine otter and southern river otter (Lutra provocax), from South America as well, are also endangered but their population sizes are unknown. From an original population of over 300,000, the sea otter was reduced to as few as 1,000 individuals by 1910 due to overhunting. While the species has now recovered, it is not yet out of danger and the Exxon Valdez oil spill in 1989 in Alaska is believed to have killed up to 10,000 sea otters, according to The Endangered Species Handbook.