Alien species of the mammalian fauna in Yakutia.
The history of introduction and invasive processes for nine mammal species, namely, muskrat, American mink, steppe polecat, sable, river beaver, muskox, wood bison, Siberian roe deer, and red deer, in Yakutia is considered. Introduction of the muskrat was carried out in 1930-1932 and this species was well adapted to the new conditions and spread in all natural zones of Yakutia. Mink was introduced into southern Yakutia in 1961-1964; its distribution is limited by environmental barriers, and the total number now constitutes 4000-5000 individuals. Steppe polecat was introduced into Central Yakutia in 1980-1983; the species is poorly adapted and its number constitutes only 150-200 individuals and tends to decrease; the population may disappear in the coming years. The reintroduction of the sable was conducted in 1948-1958 and the species now is widespread throughout the taiga part of Yakutia with the number varying at the level of 250 000-300 000 individuals. European beavers were released in 2001-2003, but animals did not survive at the places of introduction for various reasons. The muskox was introduced into different parts of the arctic zone of Yakutia from 1996 to 2017 with 199 individuals; today the number amounts to 2600 individuals. The naturalization process to subarctic ecosystems is successful. Wood bison was shipped to the republic from 2006 to 2013, and the animals were kept only in captive breeding centers until 2017. The total number doubled and reached 184 individuals. In November 2017, 30 bison were released. The modern range of Siberian roe deer was formed in the 20th century through the introduction from the adjacent territories of the Far East and southern Siberia. The species is mainly distributed in Central Yakutia, and its number constitutes 24 000 individuals. The red deer has inhabited the territory of Yakutia simultaneously with the roe deer from the same regions. Now its range covers southern and Central Yakutia, and the number constitutes 10 000-13 000 individuals.