Cost of reproduction in female non-human primates: an anthropological perspective

Abstract

Our research aims to further knowledge on the adaptive significance of reproductive processes in female primates, using a comparative approach. Our studies in semi-free ranging olive baboons (Papio anubis) show that sampled baboon mothers resume cycling and reconceive when their infants reach a relatively constant threshold mass, as predicted from interspecies life history theory. We suggest that the duration of maternal investment acted as a facultative adjustment to infant growth rates, and depends on the maternal physical and social characteristics (e.g. body mass and social rank). Energetic costs associated with reproduction are surprisingly low in our sample. Energy intake and energy expenditure do not closely predict the time to resumption of cycling. We also find a positive correlation between maternal energy expenditure and infant growth rates. Using the baboon model, this study places these results on infant growth and reproductive energetics into a broader perspective on primate life history, and explores the question of how costly non-human primate infants are. We have divided these expenditures into time and energy costs, investigating each of these during the early phase of growth.