DETERMINANTS OF NATAL DISPERSAL AND SPACE USE IN GRAY-SIDED VOLES, CLETHRIONOMYS RUFOCANUS - A COMBINED FIELD AND LABORATORY EXPERIMENT

Offspring from experimental mothers did not show significant responses in space use, dispersal tendency or social behaviour to the stress treatment of removal of mothers from maternal home ranges, but female offspring from prenatally stressed mothers grey more rapidly than offspring from control mothers. Females originating from litters with a male-biased sex ratio had the greatest tendancy to disperse, while males were not affected by litter sex ratio. Dispersing females showed significantly more avoidance behaviour in arena encounters, shared less space and had larger home ranges than philopatric females. Whether an individual C. rufocanus disperses or not thus seems to be more dependent on predisposed behavioural characteristics than to local variability in the social environment. -from Author