EN
Behavioural activity of Clethrionomys glareolus (Schreber, 1780) is modified by social factors. Interaction between sexually nonexperienced (NExp) and experienced (Exp) animals was investigated. Males and females were tested in pairs in the male home cage during 10 min encounters. Aggressive and nonaggressive behaviour was recorded, and ultrasonic vocalization was monitored by a QMC ultrasound detector. The obtained results indicate that total activity of Exp females was significantly higher than NExp females (p < 0.05). Only females exhibited aggressive behaviour toward males, but there was no difference in aggressive activity related to sexual experience. Total activity of Exp males was higher than that of NExp ones (p < 0.05). Our previous results indicate that in adult bank voles only males produce ultrasounds. In these experiments significantly more calls was recorded when Exp males were tested and compared with NExp males (p < 0.05). This study provides additional information about interaction between breeding and non-breeding animals in a bank vole population.