The temperature regime of hibernation has been studied in six ground squirrel species from 13 geographic populations living beyond the permafrost zone. It is shown that hibernation usually takes place at low above zero temperatures and that the least deep burrows are found in the zone of subzero monthly tem peratures. Populations have been found that inhabit areas where monthly temperatures during the hiberna tion period fall below zero in almost the whole range of depths at which nest chambers are located.
The range of Himalayan marmot (Marmota himalayana Hodgson, 1841) has an insular character, as it is limited by ecological and geographical barriers: in the north, northeast and east, these are deserts and the Loess Plateau, in the west - mountain peaks covered with glaciers and rivers, in the south - forests of the southern macro slope of the Himalayas. Only in the northwest of the range there is an ecological corridor. The geographical isolation of populations of marmots provokes the divergence of alarm call, which is one of the obvious genetically determined features. The results of cluster analysis based on a complex of features of the sound signal coincide with the results of analysis using nuclear and mitochondrial DNA. The projection of variability on the structure and history of the landscape contributes to understand the ecological and geographical factors of divergence as the basis for the process of speciation.
The phenomenon of life is organized in supraorganismal systems, populations and ecosystems. The main mechanisms of sustainability of these systems are: 1) the influence of limiting factors on population growth and ecosystem development; 2) the allocation of plant and animal species into ecological niches; 3) co-adaptation of plants and animals; 4) species genetic integration; 5) biocommunications. Limiting factors inhibit populations’ growth and distribution of organisms, so that populations obey the logistic growth, reaching a relatively stable climax stage. The space of limiting factors restricted by the tolerance limits of organisms forms an ecological niche of species. During long-joint evolution (co-evolution), species form co-adaptations (mutual adaptations). As a result of species genetic integrity, each new generation inherits not only adaptations for its specific ecological niche, but also a determined physical space including all the environmental factors to which the species is adapted. Consolidation of individuals with a related genotype is supported by intraspecific communication processes. Means of communication are genetically determined. Humankind is the only species on Earth that has subjugated limiting factors. As a result the population of humans shows an unlimited exponential growth, population explosion. It is a basic factor in the instability of the Nature - Society system.
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