Habitat selection of grey marmos, Marmota baibacina, in southern Altai mountains. V’bovmestoobitaniï serym sourkom (Marmota baibacina) v gorakh iujnogo Altaya. [Sélection de l’habitat chez la marmotte grise, Marmota baibacina, dans les monts de l’Altaï méridional].

Résumé

Grey marmots (Marmota baibacina) occupy mountain steppe and meadow in the Altai (M. b. baibacina) and Tien Shan (M. b. centralis) but are also found in forest steppe in southern Siberia (M. b. kastschenkoi) and in the hills of Central Kazakhstan. Grey marmots display a patchy distribution in the Altai Mountains and their populations are declining. The aim of this study was to describe habitat selection of grey marmots in the southern part of the Altai Republic (Russia). The region represents complete sequence of altitudinal vegetation zones from steppe, forest-steppe, and forest, sub-alpine and alpine vegetation. The data from 306 quadrants, including type of phytocenose, amount of vegetation and stone cover were supported by environmental andgeological data such as data on altitude (1231- 2978 m a. s.1.), exposition, slope, proximity to water, surface geology, human disturbance, surface humidity, soil type and thickness. Our results suggest that Marmota baibacina prefer cragged habitat: steep slopes with large amount of stone cover, at least 250 m from the nearest water source and with only a thin layer of soil. Altitude and exposure to sun do not represent significant factors in habitat choice of grey marmots. The marmots prefer dry areas with a small amount of herbaceous cover. The species avoids forests. Amount of human disturbance was not a significant factor affecting marmot distribution. Therefore, the main threat to grey marmot populations probably is not the habitat loss and grazing by domestic livestock, but rather extensive hunting.