Abstract: The stability of animal populations in respect of the influence of the environment is well known to be conditioned by their location in the natural habitat and their ability to establish new territories. In the peripheral regions of natural habitat, however-in the zone that is ecologically least favourable-the situation of the animal is most unstable. This is due to increased pressure of environmental factors which favour neither a high frequency of contacts between individuals belonging to sperate populations nor an increase in the number of such contatcs and their stabilization. In our opinion, this describes the situation that has come about in certain regions inhabited by the snow leopard in the Soviet Union.