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European otter(Lutra lutra)
Phylum —chordata
Class — mammalia
Order — carnivora
Family — mustelidae
Genus – lutra
Appearance
The European otter is a typical species of the otter subfamily. Brown above and cream below, these long, slender creatures are well-equipped for their aquatic habits. This otter differs from the North American river otter by its shorter neck, broader visage, the greater space between the ears and its longer tail.
Normally, this species is 57 to 95 cm (22.5 to 37.5 in) long, not counting a tail of 35–45 cm (14–17.5 in). The female is shorter than the male. The otter's average body weight is 7 to 12 kg (15 to 26 lb), although occasionally a large old male may reach up to 17 kg (37 lb).
Habitat
European otters live throughout Europe, North Africa and Asia.
Behavior
European otters have their most active time at dusk and at night. During the day they are in their dens on the land, staying cool, coming out at night to eat. They will spend several hours nightly foraging in water. They nest on land, tending to build underground tunnels to move between the two. They are solitary animals unless in a mating pair or a mothers with her young. However, sometimes they form loosely knit groups numbering as many as six animals. They are the most territorial of otter species. Their territory can be as big as 25 miles wide but is usually about 11 miles. They are able to cross territorial boundaries without incident, but aggressive behavior will occur if the same gender tries to enter a territory.
Diet
European otters are carnivores, they eat mainly fish, but they also hunt amphibians and other aquatic prey, as well as birds, eggs, insects, worms.
Reproduction
Although the mating system in European otters has not been well studied, they are thought to be either polygynous or polygynandrous (promiscuous), as both males and females associate with each other only during mating. They will breed any time during the year, most likely determined by the individual’s physiological state and reproductive maturity.
Gestation is for 60 to 70 days, each female bearing 2 or 3 pups. The pups are 99 to 122gm when born, their eyes open at one month and after two months they start to leave the nest. Weaning takes place when they are 3 months old. They remain with their mothers up to the age of 14 months, reaching reproductive maturity at the age of 2 or 3 years.
The otter can live for up to 10 years, but in the wild its average lifespan is often 3-4 years.
In captivity
Keeping an otter in captivity is not simple. Moreover, this is difficult in an urban-type apartment, since the otter can not be kept in the room all the time, although it is quite easy to train it to go to the toilet — in a box with sand. However, its excrement has an unpleasant smell. Therefore, when keeping otters at home, it is good to have your own yard, where you can make an aviary.
In this enclosure, the bottom and walls can be made of animal breeding mesh with metal corners at the junction of the bottom and walls. Under the netting lining the bottom, you should put about 20 cm of coarse gravel. The same material should be used to fix the lower part of the wall to a height of 15 cm. The same layer of river sand should cover the lower grid inside the aviary. The optimal size of the aviary is 8-16 m. The enclosure must have a pool 0.7—1 m deep. The area of its water pool should be at least 2 m, but its optimal ratio with the land area in the enclosure is 1:2. It is better to make the pool elongated, 1 m wide. For otters, a genetically fixed habitat is a water pool-the ground, so this elongated shape of the water area of the pool is optimal. Near the pool there is an otter dryer in the form of a box with a hygroscopic substrate: dry sand, peat, sawdust of deciduous trees, dry rot from rotted trunks. Such a box should contain a certain excess of lying otter. Another element of the interior of the otter enclosure is a shelter. Preferably, it should be two-chambered if the owner wants to get its offspring in the future. The entrance of the first chamber looks like the passage to the outside in the form of a rectangle of about 20 cm long and with the smallest possible cross-section area. It is covered with a sponge along the perimeter. The small area of the entrance section should be covered with a sponge on the inner perimeter. It is necessary for maximum extraction of water from the otter's hair if it tries to get wet into the shelter. The living chamber of the shelter should have an internal area sufficient for the dense lying of an adult female and its several kids. The approximate size of these premises is of 50x40x30 cm. The entrance hall can be about 30 cm long. The common shelter cover should be waterproof, possible to be raised, but heavy enough that the otters could not lift it. The lifting cover will make cleaning easier and it will be more convenient to replace wet hay with dry one, which is put on the floor. The walls of the shelter for insulation should be made double: the outer - of boards, and the inner- of plywood. It is recommended to put the sawdust between the walls in a layer of 2-4 cm.
The most important thing when keeping an otter in captivity is the selection of its diet, which provides an optimal combination of the necessary chemical elements and substances, both in composition and in calories. In the special literature, many different diets for otters are proposed. We present a kind of compromise option that combines numerous recommendations from specialists and specific opportunities. So, the weekly diet for an otter should consist of 50-80% meat and 10-30% fish. The rest can be filled with milk, butter, eggs, and frogs. Do not forget about multivitamins and substances containing calcium and phosphorus. All that you need to give the otters on a weekly basis, especially vitamins. Like other species of marten, pregnant female otters kept in captivity must be provided with sufficient vitamin and mineral nutrition. Therefore, daily food should be mixed with a child's daily allowance of multivitamins and add calcium carbonate or gluconate, as well as lay out pieces of chalk. Fish food should include not only herbivores, but also predatory fish species. The daily rate of food offered to the otter should be 0.8-1 kg.
Otter should be vaccinated annually against viral infections (carnivore plague), as well as against gastroenteritis, viral hepatitis, botulism and others, which are vaccinated against domestic dogs.
