Feeding ecology is linked to nearly all aspects of primate biology and sociality, and the development of the behaviors and knowledge associated with feeding is the best-documented predictor of survival and reproductive success. Despite its significance, the ontogeny of the behaviors and knowledge associated with feeding remain poorly understood. Sex differences in feeding may be key in minimizing feeding competition and facilitating permanent social groups, but also add further social complexity to the ontogeny of feeding ecology. Sex differences in feeding are linked to times of increased costs of reproduction to females, to permanent niche partitioning strategies, or to physiological differences due to sexual dimorphism. While sex differences in feeding ecology of adults are documented across the primate order, the timing and mechanisms of their development are unclear. This project will integrate behavioral, stress endocrinology, and forest phenology data from ring-tailed lemurs at the Beza Mahafaly Special Reserve, Madagascar to identify when sex differences in feeding develop. It will examine how differences are related to costs of reproduction or niche partitioning, how habitat quality and stress impact the development of juvenile ring-tailed lemur feeding, and how social mechanisms shape these differences. Habitats of varying quality, including human-degraded habitats, will provide a cost gradient to test how the development of sex differences is related to food availability, mortality risk, and stress-factors which all contribute to primate life history evolution. The comprehensive dataset generated through this project will include the creation of a framework to test long-term developmental questions relative to health and reproductive success. This can then be used to explore future comparisons among haplorhines and strepsirhines aimed at understanding evolutionary patterns of primate feeding and stress. Understanding the ontogeny of feeding differences across a phylogenetically broad array of primates assesses which behavioral and developmental strategies of this key aspect of life yield successful adults and how these strategies differ or are similar across taxa. This project also has important conservation implications by addressing the effects of habitat degradation on lemur growth and development and how stress fluctuates with ring-tailed lemur life history stages. This information is highly relevant, as 90% of Madagascar's forest habitat has been degraded by human use. This project will additionally train a Malagasy Master's student and an American assistant in methods of behavioral ecology. .
