Effects of Isolation on Aggressive Interactions of Same-Sexed Pair and Opposite-Sexed Pair in the Domesticated House Musk Shrew (Suncus murinus)

Abstract

Males and females of the domesticated house musk shrew (Suncus murinus), housed under the isolated or grouped condition from 30 to 60 days of age, were tested in 5 times for interactive behaviors with a partner of same sex. Then, they were paired with a partner of opposite sex in the 6th session and observed for sex-related aggressive interactions. Isolation effect of enhancement of aggression was clearly shown in the same-sexed pairs, while repeated encounters did not influence on aggression. On the contrary, isolation effect was not found in the interaction between opposite-sexed mates. This result suggested the mechanism of the aggression in the same-sexed pair was different from that in the opposite-sexed pair in this species.