The paper presents the results of a study of the asymmetry in the use of the forelimbs in 42
beavers from the Voronezh beaver nursery and Voronezh Reserve. The aim of this study was
to study the influence of environmental conditions on the manifestation of left-right
preferences in the forelimb use in various types of actions in Eurasian beaver. The
manifestation of such lateralization was evaluated at the individual and group levels. We
showed that beavers living in natural conditions and engaged in construction activities had a
higher degree of unimanuality and a higher percentage of animals with a pronounced
manual preference. A new, adapted for large rodents, type of a test task for the forced use of
one forelimb is proposed.