THE IMPACT OF THE DIFFERENT PERIOD OF OCCURRENCE OF THE EUROPEAN BEAVER POPULATION ON ITS FEEDING BEHAVIOR AND IMPACT ON THE ENVIRONMENT.

The aim of the study was to determine the influence of the period of occurrence of the European beaver (Castor fiber L.) population on foraging strategies and on the diversity of the species of cutting trees and shrubs. Two beaver populations at different stages of development - a younger (42yr) population from the Kampinos National Park and an older (72 yr) population from the Wigry National Park were studied. Both populations foraged according to the Optimal Foraging Theory (OFT), according to which the distance to available food depends on its size and the distance to reach it. The dominant factors modifying the foraging behavior of beavers and their foraging ranges were the presence of a dam, the availability of preferred species. The greater diversity in the areas where beaver are found may be the result of both beaver activity and the selection of more attractive areas for dam construction. [ABSTRACT FROM AUTHOR]