The reproduction and postnatal development of the bushveld gerbil Gerbilliscus (formerly Tatera) leucogaster was studied in the laboratory. Nineteen pairs produced 23 litters. Mean litter size was 3.5 and gestation was 21-22 days. Neonates weighed 3.7 g on average and were altricial. Development was slow, with eyes usually opening 16-18 days after birth, and weaning occurring by about 24 days of age. The earliest age of sexual maturity was 6.6 weeks in females and 9.9 weeks in males. A comparison with other studies of G. leucogaster, and with closely and distantly related similar-sized murid rodents, indicates that reproduction generally varies with geographic location, and that the slow postnatal development of G. leucogaster appears to be phylogenetically constrained.

The study of social behaviour can give us important insights into the social and mating system of a species or population. We investigated male-female interactions in captive bushveld gerbils, Gerbilliscus leucogaster, to gain insight into the social behaviour and mating structure. We conducted two experiments. In experiment 1, we studied the interactions between two strangers for a week in a three-tank setup, which tested behavioural variation spatially and temporally. Although tolerance between strange males and females increased with time, it remained generally low throughout the experiment. Females appeared to be cautious of males initially, but they later became aggressive towards them. Males showed an increase in submissive behaviour over time. The 'home' cage did not appear to be defended by either sex. In experiment 2, we investigated the social interactions of male-female pairs during pregnancy and lactation. Aggression persisted throughout the study and amicable behaviour was low; females were much more aggressive than males. We did not detect changes in social behaviour with the progression of pregnancy and lactation. We suggest that pair bonding is unlikely and that promiscuity is the most probable mating system. Female aggression may be related to mate choice prior to mating and mate exclusion thereafter, while it may be a response to infanticide risk during pregnancy and lactation.

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