Ultrasonic calls of bank vole pups isolated and exposed to cold or to nest odor.

Bank vole pups produce ultrasounds when isolated from the nest, as other rodents do. The present study was intended to elucidate the possible interaction between the social stress of isolation from the mother and the physical stress of low ambient temperature during the nesting period. Although bank vole pups removed from nests and monitored at nest temperature vocalized at high frequency, the number and duration of signals increased at lower ambient temperature.

Prenatal stress modifies behavior in offspring of bank voles (Clethrionomys glareolus).

The aim of the present study was to investigate the effect of prenatal stress on behavior of adult bank vole males and females. Pregnant females were submitted to stress by short encounters of two females at the same stage of pregnancy, to crowded condition by transfer to a cage with four to five nonpregnant females, or stressed by immobilization. The stressors were applied on Days 13, 14, and 15 of pregnancy.

Prenatal stress affects the rate of sexual maturation and attractiveness in bank voles.

Field studies reveal that bank vole females' mobility and aggression increase during pregnancy. Here we investigated the reaction of pregnant females to social stress evoked by short but frequent meetings with another female at the same stage of pregnancy. The stress neither evoked pregnancy termination nor affected pregnancy duration but had a long-term effect on the reproductive activity of the offspring.

Sociogenic stress and rodent reproduction.

Social stress, which is a part of the interaction between animals, can be defined as the set of physical stresses caused specifically by the presence and actions of certain conspecifics. Dense populations are characterized by considerably increased intermale and interfemale aggressive behavior. This establishes a hierarchy which influences reproduction of the animals.

Removal of the olfactory system modifies male bank vole behaviour in the presence of females.

The role of the olfactory and vomeronasal systems of male bank voles in behavioural interaction with females was investigated. Bulbectomy (OBX), but not vomeronasalectomy (VNX), resulted in a decrease of female-stimulated ultrasonic calling by males, manifested as longer latency to the first call and fewer calls by OBX males in comparison to VNX or sham-operated (SHAM) animals. OBX males showed significantly fewer non-aggressive approaches but more attacks toward females.