Mammals of Baikal basin

Mammals of Baikal basin Up-to-date fauna of mammals, of the lake Baikal basin is a complex genetically heterogeneous formation. Species composition is presented by 69 species of mammals that form 6 types of territorial communities (populations) - mountain-tundra, taiga, steppe, meadow-swamp-shrub, by-water, synanthropic. The most ancient inhabitants of the basin are undoubtedly species and communities spatially connected with landscapes of river valleys - by-water, meadow-swamp-shrub and, partially taiga. The steppe communities formed almost at the same time. The complex of mountain-tundra species started to form considerably later. The youngest type of communities is synanthropic complex of mammals. Long-term development of the lake basin resulted in an unique ekosistem whose natural regime caused a number of peculiarities of nowadays fauna and spatial structure of mammals communities: 1. Great species heterogeneity of mammals fauna that can be compared by abundance with the neighbor regional faunas. 2. Peculiarities of orography and hydrology caused formation of three nature sektors of the lake shores (Baikalsk-Primorsky, Olkhinsk-Khamar-Dabansky, Barguzinsk-Ulan-Burgassky). Mammals fauna of these sektors has been for a long time developing in conditions of isolation. 3. Extremely high mosaic of mammals communitiens. This phenomenon is mostly pronounced on the western shore of Baikal (Baikal ridge). Here, at 8-10 km distance from the shore line to axial parts of the ridge one can find the whole set of communities existing in the basin. 4. Inversion of high-altitude distribution of some species and communities. The species of the tundra communities (Marmota camtschatica, Alticola macrotis, Ochotona hyperborea, Rangifer tarandus) dwell by the shore line in the northern part of the basin, and vice versa in the southern part (Khamar-Daban randge) some steppe and taiga species (Citellus undulatus, Sicista betulina, Talpa altaica) have adapted for dwelling in subalpine belt. Specific features of the basin geographical situation, fauna and communities of mammals create favorable conditions for a series of experiments that are of generally scientific and applied significance (barrier role of lake Baikal, island faunas, minimum viable populations, minimum territorial sizes for survival of populations, formation of species and evolution of populations under conditions of spatial isolation, etc.).