FACTORS AFFECTING PAIR COMPATIBILITY IN CAPTIVE KANGAROO RATS, DIPODOMYS HEERMANNI

Captive propagation is a critical component of the Morro Bay Kangaroo Rat Recovery Plan, but past attempts to breed this and other kangaroo rat species have had mixed success. In three experiments using a close ly related surrogate species, the Lompoc kangaroo rat, we evaluated th e effects of familiarity and long-term housing experience on the behav ior of captive males and females during dyadic encounters in an attemp t to devise husbandry methods most conducive to reproduction. Females exhibited less aggression with and were more likely to allow physical contact with familiar males, provided the males had had previous socia l experience, such as that provided by living in close sensory contact with female conspecifics. Socialized males (those housed adjacent to females, separated from them by a wire mesh screen) were cautious, rat her than persistent, when interacting with unfamiliar or anestrous fem ales. Males housed in isolation from conspecifics were persistent whet her or not they were familiar to the female. Pairs with very long peri ods of familiarity exhibited more nonaggressive contact than newly acq uainted pairs. Results suggest that housing structures allowing longte rm sensory contact between potential mates may improve breeding succes s in kangaroo rats and other solitary, aggressive species. (C) 1995 Wi ley-Liss, Inc.