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Lake Baikal Mountain Vole

Alticola olchonensis

French: Campagnol du Baikal / German: Olchon-Gebirgswiihimaus / Spanish: Topillo de montana del Baikal

Other common names: Baikal Mountain Vole, Olkhon Mountain Vole

Taxonomy. Alticola argentatus olchonensis Litvinov, 1960, EC Lake Baikal, Olkhon Island, Irkutskaya Oblast, S Russia.

Alticola olchonensis was long regarded as part of A. argentatus or synonymized with A. roylei, A. tuvinicus, or A. macrotis . It was elevated to a full species in 2002, which was subsequently supported by molecular phylogenetic analysis. Alticola olchonensis was recently classified as a member of Aschizomys, but that was refuted by molecular data. Monotypic.

Distribution. Olkhon I and adjacent small islands in the Maloye More (Little Sea) of Lake Baikal and contiguous mainland (Russia).

Descriptive notes. Head-body 109-121 mm, tail 33-37 mm; weight 24-43 g. The Lake Baikal Mountain Vole closely resembles the more widespread Tuva Mountain Vole (A. tuvinicus). Tail is relatively short (27-32% of head-body length), bicolored, and densely haired; it has a distinct tuft. Fur is long and soft, gray and washed brown dorsally and whitish with buffy shades on belly. Ears are buff in some individuals. Skull is strong and shallow, with long diastema and large bullae. Molars are rootless, with enamel pattern typical for species of Alticola .

Habitat. Steppe, rockysites, and talus slopes on the bank of Lake Baikal.

Food and Feeding. The Lake Baikal Mountain Vole hoards plants for winter; caches contain up to 2-6 kg of dry plants.

Breeding. Female Lake Baikal Mountain Voles have 1-2 litters/year.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Endangered on The IUCN Red List. Status of the Lake Baikal Mountain Vole is justified by its small extent of occurrence (2189 km?) and a decline in the quality ofits native steppe habitat, which is under thread from human encroachment and by aridization and desertification.

Bibliography. Bodrov et al. (2016), Borisova et al. (2001), Yudin et al. (1979).