Nekotorye adaptatsii sourkov kak sledstvie istoritcheskikh izmeneniya ouslovii ikh jizni [Quelques adaptations des marmottes suite à des modifications historiques de leur habitat. Some adaptations of marmots as the result of historical modifications of their habitat conditions].

Résumé

The marmots (Marmota) vary not only in morphology but in adaptations too. However the comparable data and especially the experiences of taxonomical and geographical variation analysis of marmots ecology are evidently insufficient. It is supposed that the marmots as the ecological form of the winter-hibernating, grass-eating, burrow-building animals carry the features formed in the cold epochs of the Pleistocene when the hibernation had origin during long cold periods as one of the adaptations to the periods of famine (Kalabuhov, 1985). The hibernation of marmots correlates with their specialization on sappy food fruit full of proteins and carbohydrates, with their seasonal rhytms of fat accumulation and expense, with their interrupted diurnal activity, with the pecularities of their shifts determining the familiarization and using of territory. The length of hibernation varies from 3 (M. monax) to 9 months (M. bobac shaganensis, M. camtschatica bungei) for the generality of species-6-7 ones. The role of sappy food decreases in the trend : M. menzbieri, M. marmota, M. camtscatica, (maybe M. caligata and M. broweri), M. caudata, (maybe M. flaviventris), M. baibacina, M. sibirica, M. bobac (shaganensis). The most range of food types utilizated is inherent in M. caudata and the marmots of "bobac group". But even such stenofage as M. menzbieri at the upper border of its distribution eats early in spring mainly underground parts of plants (Kapitonov, 1968). It tally with the known differences in the food of the phytofages of high-mountainous and plainous steppe-like ecosystems (Zlotin, 1975). The variability of ecological potential is noticable even in the separate colonies. This fact is possibly connected with the continuing selection of the lines most talling with the current conditions. It’s confirmed by the examples of different adaptations including the energetical processes closely connected with the changes of climate. It’s significant that the marmots vary by the level of fat accumulation (20-25% of body weight) less than by its rate, M. camtschatica bunge and M. broweri have the highest rate-they accumulate during short time about 35% of the fat with especially valuable oily acids. It correlates with the long-time hibernation and the increased expense of this fat. There (and for other examples) we can see the differentiations connected with the demographical and ecological pecularities of concret populations. The territorriality and the shift ability had great importance for the forming of marmots agreals. As the initially-mountainous animals many species of marmots have disrupted family areas with seasonal and annual changes of burrows and pastures. It secures the survival with the changes of weather and climate causing the displacements of areal borders up-or downwards and the far migrations. In plains the system of territory using is simplified that decrease the vulnerability of marmots. The genetical variability of adaptations is possibly represented variously in different forms of marmots. The ecological variants spectrums are, it seems, connected with the history of concret forms. They determine in high degree the possibility of their adaptations to new conditions including the human press.