Beaver Census

The Prioksko-Terrasny Reserve held a census of beavers. In moderate climate zone, it is usually conducted in November, when beavers finally settle on the place of upcoming hibernation.

The autumn period is chosen due to the peculiarity of the habitat of these animals. In summer beavers predominantly feed on herbaceous vegetation, and out of convenience, they can build temporary dams. Therefore, in summer it is more difficult to determine the center of beaver settlements, to draw a line between the settlements located nearby, as well as to determine the strength or number of animals in populations.

In winter, beavers mainly eat the bark of trees, the most nutritious of which includes aspen, then willow, and then, finally, birch bark. It is the branches of these trees that beavers store for the winter in their ponds near the entrance to their home, a burrow or a hut. These stocks of food look like a bunch of brushwood covered with water. In the winter, beavers swim to their stocks under the ice, take a branch and pull it home, where they gnaw it.

To create their winter stocks, beavers cut down trees and shrubs, growing on the banks. All the dams and ponds built over the summer are no longer necessary for them, with the exception of those by tree cutting and those where they stay for the winter. Cuttings with leading to them trails, food stocks near hollows and a relatively small number of well-manicured dams with ponds allow to be confident enough to determine the location and strength of beaver settlements. By the size of the footprints in the mud, the width of the front teeth, marked on the chewed wood, the age of the animals can be determined. The amount of stocks, the number of cuts, the covered area, the presence or absence of a cascade of ponds, the size of paw prints or front teeth allow to evaluate approximately the strength of the settlement and its age structure.

This year’s early frosts and heavy snowfalls have complicated the beavers’ preparation for the winter. In some settlements, they dragged branches underwater through a hole in the ice, and in some cases even broke the ice.

In general, the number of beavers in the reserve this year is not much different from the previous years. If in 2014 there lived 38-60 (on the average 49) beavers, and in 2015 there were 36-58 (on the average 47) animals, this year the census showed the result of 30-40 (on the average 35) beavers.

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