Monitoring and prospects for conservation and rational use of the resources of the Eurasian beaver (Castor fiber Linnaeus, 1758) on the example of the Samara Region

The paper examines characteristics of the Eurasian beaver population (Castor fiber Linnaeus, 1758) on territories with different anthropogenic load. Monitoring the beaver population and habitat, including the landscape basis and natural zoning with the allocation of natural, natural-anthropogenic and anthropogenic territories as natural ecological systems allows you to manage and rationally use the resources of these animals. Previously there were mainly natural territories in the studied region, however with the growth of the human population and its economic activity their properties have changed. According to biotic criteria, geochemical circulation, significant (formerly natural) territories functionally already correspond to natural-anthropogenic and anthropogenic objects, since the supply of fodder, population density and density of animals have changed. According to natural zoning, taking into account the identified changes in the habitat of beavers (by biotic criteria), we have examined their territorial distribution as well as the number of settlements in various natural objects of the region. On the studied rivers the density of the beaver population in the channel decreases in the following order: natural territory → natural-anthropogenic → anthropogenic, but the indicator of private abundance (the density of animals on the territory where beavers live directly) and aggregation (crowding of individuals) increases. The population density of the river bed of the studied rivers by beavers on anthropogenic territories is from 0,9–3,7 individuals/km, which is lower than on natural and natural-anthropogenic territories, where this indicator is from 1,5 to 6 individuals/km. The length of the river bed, where beavers live directly, without taking into account significant buffer zones, varies in natural areas from 60 to 100%, which is more than in areas with anthropogenic load, where this indicator in the study area decreases to 40%. A decrease in the size of river channel sections suitable for beaver colonization leads to overcrowding (aggregation) of individuals. Compared with the total density of beaver population in the river channel 0,9–3,7 individuals/km of the channel (excluding the Kondurcha River – 6 individuals/km of the channel) the population density, locally, on anthropogenic and natural-anthropogenic territories increases to 4–7,5 individuals/km.