Abstract # 5845 Event # 18:

Scheduled for Saturday, September 13, 2014 01:30 PM-01:45 PM: Session 6 (Henry Oliver)


SEX AND BIRTH ORDER PREDICT JUVENILE GROWTH AND SURVIVAL IN CAPTIVE RHESUS MACAQUES (MACACA MULATTA)

C. L. Nunez1,2, M. N. Grote4, M. Wechsler2 and K. J. Hinde2,3
1Duke University, University Program in Ecology, Department of Evolutionary Anthropology, 107 Biological Sciences Building, Durham, North Carolina 27708, USA, 2Brain, Mind, & Behavior Unit, California National Primate Research Center , 3Department of Human Evolutionary Biology, Harvard University, 4Department of Anthropology, University of California, Davis
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      Female mammals may begin to reproduce before achieving somatic maturity. As a result, primiparous mothers face tradeoffs between allocating energy to reproduction or their own continued development. Constraints on primiparous females are associated with greater reproductive failure and first-born infants often have slower growth and higher mortality and morbidity than do infants born to multiparous females. Effects of deficits in early life maternal investment may persist even after weaning when juveniles are no longer dependent on maternal care and mother’s milk. We investigated the long-term outcomes of both first-born and later-born offspring, as a proxy for maternal investment, in a large sample of Macaca mulatta assigned to the outdoor breeding colony at the California National Primate Research Center (N=2724). A joint Bayesian model for growth and mortality over the first three years of life allowed us to explicitly connect growth rates to the likelihood of survival. As expected, we found that males are born heavier and grow faster than females. However, contrary to expectations, later-born males face substantially lower survival probability during the first three years, while first-born males survive at higher rates that are similar to females of both parity classes. These findings suggest that differential levels of maternal investment shaped by life history evolution have a tangible influence on the growth and survival of offspring,even within a captive context.