Otter

This species is perhaps more aptly named the Eurasian otter because it is found as far east as Manchuria. It is also found as far north as the tundra line of Siberia and Scandinavia and as far south as the coastal plain of North Africa.

European otters spend most of their waking hours in water, though they build their nests on land. The nests are often made up of a network of tunnels dug into the river bank or running through roots and thick shrubs. Each otter defends a short stretch of river bank, marking its territory with secretions from a scent gland under the base of the tail.

Within the territory an otter has a designated area for entering the water, basking in the sun and playing. Otters are very playful. They are often seen rolling in grass and sliding down muddy slopes into the water.

The European otter has a brown coat, which is paler in Asian populations. The feet are generously webbed to aid with swimming. Each foot is also equipped with large claws.

Otters can dive for up to two minutes at a time. Once in the water they use sensitive whiskers to detect the currents produced by the movements of their prey. Air bubbles trapped in the fur keep the skin dry.

In spite of its wide distribution the otter population has declined, particularly in Europe, although there are now signs that it is increasing again.

The otter population has suffered from pollution of its waterways, which has resulted in a loss of fish and therefore food. Toxins have also passed up the food chain, adversely affecting their health. However, environmental improvements coupled with release schemes have seen otters successfully reestablished in some areas. Territorial by nature, they mark their territory with their droppings, called spraints.

Distribution: Occurs across Europe up into Scandinavia, and in a broad band through the more temperate latitudes of Asia. Also present in northwestern North Africa.

Habitat: Rivers and lakes.

Weight: 7 - 10 kg (15 - 22 lb); males are heavier.

Length: 92 - 165 cm (36 - 65 in); up to 30 cm (12 in) tall.

Maturity: 2 years.

Gestation Period: 63 days; embryonic development does not begin straight after fertilization.

Breeding: 2 - 3; weaning occurs at around 70 days.

Food: Primarily piscivorous, feeding on a variety of fish, although will also eat frogs and water birds.

Lifespan: 5 - 10 years in the wild; up to 20 in captivity.

Status: Vulnerable.

Coat

The water-resistant coat is generally dark brown over the back and paler on the underparts.

Whiskers

The whiskers help the otter find its way and locate prey underwater.

Feet

Webbed paws help otters to swim more effectively, and end in sharp claws.

Tail

A relatively long and powerful tail helps the otter to swim well.

OUT OF SIGHT

Cover is very important for otters, so they can emerge undetected from the water, although they rarely stray far on land.

African Clawless Otter

This species is slightly larger than its close African relative, the Congo clawless otter. It lives in eastern and southern Africa. Like its relative, the African clawless otter has feet with less webbing than most otters and only rounded claws on the hind feet.

The African clawless otter swims and dives as well as other otters, although its feet have only small connecting webs. As its name suggests, this otter has no claws other than tiny nails on the third and fourth toes of the hind feet. It has less dense fur than most otters so has not been hunted as extensively.

Crabs are the most important item of the clawless otter's diet, and it is equipped with large, strong cheek teeth for crushing the hard shells, it also feeds on mollusks, fish, reptiles, frogs, birds and small mammals. Like most otters, it comes ashore to eat and feeds from its hands. Clawless otters seem to be particularly skilful with their hands. They locate this prey by touch, using their dexterous, clawless hands.

Clawless otters do not dig burrows, but live in crevices or under rocks in family groups, in pairs or alone. The litter of 2 to 5 young stays with the parents for at least a year.

Range: Africa: Senegal, Ethiopia, South Africa.

Habitat: Slow streams and pools; coastal waters, estuaries.

Size: Body: 37 - 39 in (95 - 100 cm); Tail: 21 1/2 in (55 cm).

Congo Clawless Otter

Congo clawless otters live in the waterways of the mighty Congo Basin, the largest river system in Africa. The otters avoid the main watercourses and are more often found in streams, swamps and ponds in the deep tropical rainforest.

These bodies of water have little or no current and are consequently heavily clouded with sediment. Lacking claws, these nocturnal otters are much better able to feel for slippery prey in this muddy water and overturn stones in search of food than their clawed cousins.

Clawless otters also have shorter whiskers than other species. This suggests that they are not as reliant on whiskers for detecting prey underwater as other otters. This species of otter catches fish and frogs and collects prey, such as shellfish, from the muddy bottom of the river.

Unusually for otters, this species has no claws or webbing on its forefeet. There is a small amount of webbing on the hind feet and a simple peg-like claw on the three middle toes. Clawless feet help the otters to feel objects under muddy water as they search for prey.

The otter's teeth are also more suited to a wide range of food than other otters, which all have teeth adapted for gripping slithering fish. This feature, along with the short whiskers, suggests that Congo clawless otters spend a lot more time foraging on land than other species. Little is known about the breeding habits of this allusive species, but they are probably broadly similar to other species.

Distribution: Congo River Basin.

Habitat: Swamps and ponds in tropical rainforests.

Food: Fish, frogs and shellfish.

Size: 78 - 98 cm (30.75 - 38.5 in); 15 - 25 kg (33 - 55 lb).

Maturity: 1 year.

Breeding: Litters of 2 - 3 young.

Life span: 15 years.

Status: Unknown.

Spotted-necked Otter

These otters live in the Great Lakes region of East Africa. They do not swim in cloudy water and are often found foraging beside clear mountain streams. As its name suggests, this species has white spots on its neck and throat against a background of brown fur. They have strongly webbed feet and large claws, which suggests they catch most of their food while swimming in open water. Fish makes up most of their diet, but they also eat frogs, freshwater crabs and insect larvae.

Size: 85 - 105 cm (2.8 - 3.4 ft); 4 kg (8.75 lb).

Short-clawed Otter

This otter is one of the smallest otters in the world and, as its name suggests, has very small claws. These claws are in fact tiny blunt spikes that barely protrude beyond the tips of its paws. Unusually, the feet are webbed only to the last knuckles - not to the ends of the toes, as in other otters. These adaptations mean that it has considerable manual dexterity and sensitivity of touch compared to other otters.

Short-clawed otters tend to catch food using their nimble paws rather than their teeth. They favour mostly crabs and molluscs, and have developed large, broad teeth for cracking the shells. Other food includes frogs and small aquatic mammals. They rarely eat fish, and so there is little competition for food.

The short-clawed otter's finger-like front toes make this the most dextrous of the otters. Its front paws are more handlike than any other otter, allowing it to feel for food in shallow water. This otter has short dark brown fur with pale markings on its face and chest.

This Asian otter is highly social, and breeding pairs often stay together for life. Small social groups of up to 12 animals are common, and 12 distinct calls have been recorded. These otters also make rewarding pets, and some have even been trained to catch fish by Malay fishermen.

Distribution: Indonesia and the Philippines.

Habitat: Freshwater wetlands.

Food: Crabs, molluscs and frogs.

Size: 450 - 610 mm (18 - 24 in); 1 - 5 kg (2.2 - 11 lb).

Maturity: 2 years.

Breeding: 1 - 6 young born yearly.

Life span: 20 years.

Status: Threatened.

Marine Otter

The marine otter, or sea cat, lives on South America's Pacific coast, from its southern tip to northern Peru. Small populations also exist on the South Atlantic coast of Argentina. This is the smallest of the American river otters, which form a separate genus to the Old World otters and the sea otter. It is the only river otter that lives exclusively in the sea. It occupies exposed rocky coasts, sheltering from rough seas and strong winds in caves and crevices. Marine otters eat fish and shellfish such as crabs and mussels. They sometimes catch birds and small mammals.

Size: 90 cm (35.5 in); 4.5 kg (10 lb).