We addressed the relative contributions of maternal rank and sociability to the survival of infant vervet monkeys (Chlorocebus pygerythrus) to nutritional independence (~210 days) in a resource-poor environment. Data from 153 infants across three troops and 10 birth cohorts indicated a pre-weaning mortality of 30% (Range: 9%-85%), with a median age at death of 50 days. In addition to the consequences of resource availability, increased infant survival was independently and equivalently associated with higher maternal rank and a greater number of maternal spatial partners. We use this outcome to suggest that apparent discrepancies in the relative importance of different maternal attributes in determining reproductive outcomes may be resolved by considering more closely local sources of infant mortality.