The lesser white-toothed shrew (Crocidura suaveolens) is a common but infrequently studied small insectivore. Because of difficulty in conducting direct observations in nature on the social behavior of this species, we designed a laboratory study to evaluate its social organization. We conducted encounters between strange pairs of shrews, simulating such interactions in the wild, in neutral sites, or between “resident” and “intruder” shrews. The effect of familiarity was tested by observing encounters between the same pairs immediately after the encounter and 24 h later. Sexual conflict was observed between male and female shrews, with males trying to mount females during the initial encounters and intensive female agonistic behavior toward the males. In addition, whereas males were equally aggressive to both sexes, female aggression toward another female was rarely observed. Familiarity between the pair resulted in decreased levels of aggression and increased tendency to spend time with the opponent regardless of its sex. We suggest that sexual differences in behavior of shrews result from differences in breeding strategies: males attempt to mate with the maximum number of females, and females try to establish long-term relationships with specific males. Long-term familiarity maximizes the pair bond, maximizes the female's reproductive success, and may allow free access of females to food resources in stable overlapping home ranges of males prior to parturition.
lesser white-toothed shrew