Ecology of sable (Martes zibellina L.) in Western Yakutia

The population grouping of sable in the Western Yakutia has resulted from natural moving of autochthonic sables of the northwest of Yakutia and Krasnoyarsk region, and also descendants of the Baikal region sables, aliens in the pool of the Lena river. During last decade the population of west-yakut grouping reached the ceiling level inconnection with the increased migration activity and inflow of sables from adjacent territories. During current time its growth has stopped under the influence of an intensive craft, there was a reduction tendency. The age-sex composition was different from the big share of underyearling species (68,8 ± 1,8%). Adults sables occupied 31,2 ± 1,8%, including males 20,7 ± 1,6%, females − 10,5 ± 1,2%. The overwhelming majority was made up by small animals on the second year of life (64,1 ± 3,3). More senior age groups aren't numerous: till 3-5 years lived 5,7%, till 6-8 years - 2,9%, till 9-10 years and more senior-1,3% of individuals from the number underyearling. Especially big withdrawal is with females of reproductive age. Among young sables their parity with males is 1:1, with adults - 1:2. Breeding nucleus is formed by sables of 1-5 years representing 90,8% of an adult livestock. 31,4% of adult females took part in reproduction. Among one-year-old females 13,6%, at the age of two and more years - 64,0% of individuals bred. Potential breeding power of females equaled 3,14 ± 0,26 and was above than in alien (2,78 ± 0,15) but it is less than in native populations (3,43 ± 0,21), what reflects geographical variability of breeding power. The basis of winter food was made by animal forages (84,8%). Vegetative forages were eaten in a small amount that is typical of light coniferous taiga with impoverished phytocenoses. According to the quantity of well-fad individuals (32,9 ± 1,8%) and the index of their fatness (1,51 ± 0,09 g/kg) the grouping took an average place between alien (60,1 ± 2,3% and 1,64 ± 0,3) and autochthonic (28,1 ± 1,7% and 1,04 ± 0,15 g/kg) populations. According to morphological signs (weight and length of a body and coloring of a fur cover) it is closest to the autochthonic form which has developed in similar nature and climatic conditions. It appears from this that the west-yakut sable was generated under prevailing influence of native populations and is closer to the Yenisei subspecies.The accelerated alternation of generations in a breeding nucleus, its close dependence from replenishment by the young growth, caused by a cold climate and the impoverished forage reserve make an important demographic feature of the west-yakut grouping of a sable that is necessary to consider at forecasting of its number and trade operation.

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