Perception Channels: tactile ; chemical
IUCN Red List of Threatened Species: near threatened
In the past river otters were considered to be the main competition of fishermen and a bounty was paid by the Swiss goverment for each otter killed. (Sivasothi 1994)
The pelts of river otters are considered to be valuable to humans. (Grzimek 1990)
Lutra lutra individuals eat fish, crustaceans, clams, small mammals and amphibians, birds, eggs, insects, worms, and a small amount of vegetation. They use their vibrissae (whiskers) as sensing organs underwater to monitor the movements of fishes and other prey. River otters hunt and feed several times a day, consuming about 1kg of food daily. (Grzimek 1990, MacDonald 1984, Heggberget 1994)
Lutra lutra inhabits most of Eurasia south of the tundra line and North Africa. (MacDonald, 1984)
Biogeographic Regions: palearctic (Native )
Lutra lutra forage in water and nest on land. They inhabit rivers, lakes, streams, freshwater and peat swamp forests, ricefields, ocean shores, fjords, caves, and terrestrial habitats adjacent to waterways. Covered dens and dry resting sites are found in earth tunnnels, tree roots, boulder piles, shrubs, and banks. In its territory of 1 to 4 miles, each river otter has fixed locations for getting into and out of the water, rolling, sunbathing, and sliding on "otter stairways". (Grzimek 1990, Sivasothi 1994)
Aquatic Biomes: lakes and ponds; rivers and streams; coastal
Average lifespan
Status: captivity: 22.0 years.
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 6750 g.
Average basal metabolic rate: 25.104 W.
Lutra lutra has a continuous breeding cycle and female otters have a continuous estrus cycle. Mating can take place either in water or on land. The main mating season is from February to March and July. Gestation lasts 60 to 70 days and weaning occurs at 3 months. Each female river otter usually gives birth to 2 or 3 cubs which are 99 to 122gm at birth. The cubs' eyes open after one month and they begin to leave the nest after two months. The young stay with their mothers for up to 14 months and reach sexual maturity after 2 or 3 years. (Heggberget 1994, Grzimek 1990)
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 110.5 g.
Average gestation period: 61 days.
Average number of offspring: 2.
Average age at sexual or reproductive maturity (male)
Sex: male: 548 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 548 days.
