Lutra lutra Linnaeus, 1758
Synonyms: Mustela lutra L., 1758; Lustra vulgaris Ercsl., 1777; Mustela lutra piscatoria Kerr., 1792; Lutra nudipes Melch., 1834; Lutra roensis Ogillby, 1834; Lutronectes whiteleyi Gray, 1847
Common names: Engl: Common (Eurasian, European, Old World, river) otter; Bulg: Vidra; Rom: Lutra; Russ: Obyknovennaya, rechnaya vydra; Ukr: Vydra richkova
Taxonomic description: Long slender body, short legs, long tail with thick base and tapering evenly. Broad muzzle, small ears, all four feet webbed. Swims smoothly, watching from water with only eyes and nose above surface. Head-body length: male 60-90 cm; female 59-70 cm. Tail length: male 36-47 cm; female - 35-42 cm. Hind-foot length: 1-13.5 cm. Shoulder -height : 30 cm. Weight: 6-17 kg. Dental formula: 3/3, 1/1, 4/3-4, 1/2=36-38.
World level: EN
Black Sea Regional level: EN
Subregion level: EN
Distribution: Ubiquitous throughout Europe, but not Mediterranean islands, Algeria and Morocco, Asia Minor, India, Indo-China, China and Japan, and Central Asia and South Siberia. Black Sea Coast: in the rivers flowing into the Black Sea. The rivers of the Bulgarian Black Sea Coast are: Rezovska, Veleka, Diavolska, Ropotamo, Kamtchia, Batova and some of the lakes and swamps near the Black Sea Coast.
Habitats type, Critical habitats, Limiting factors: Fresh water, where suitable cover (rivers, lakes, canals, marshes, sometimes ditches with only a few cm of water); also marine (coastal and estuaries). Lives in holt: cavity in bank, hollow tree, between roots, rocky clefts or tunnels in peat. Largely nocturnal, with a period of inactivity in the middle of night.
Biology: Carnivorous. Principally fish and occasionally other vertebrates (water rodents especially Water Voles, amphibians and invertebrates - crabs, worms, insects). Lives in family groups of one or more females and cubs of the year occupying group territory, otherwise adults solitary and come together only for a few days at mating. Breeding is at any time of the year but highly seasonal in summer. Earliest known breeding: male-1.5 year; female- 1 year 10 months. Gestation: 61-63 days. Litter size - 1-5 (usually 2-3). Taken to water and encouraged to swim around 3 months. Weaning age 16 weeks. Parental care by female only. Cubs remain with mother for 10-12 months.
Population trends: Relatively stable populations in clear rivers and highly sensitive to water pollution and poaching.
Threats: Environmental pollution, habitat restriction, poaching pressure.
Conservation measures taken: Some of the habitats are included in reserves and protected wetland areas.
Conservation measures proposed: Regular recording of the species numbers in the region and water quality control.
Compiled by: S.Gerasimov