Cooperative breeding is of significant interest in evolutionary biology and the relevance of female-female competition to the operation of sexual selection is gaining appreciation; yet, the determinants of reproductive status (breeder vs. helper) in cooperative systems and the mechanisms underlying female aggression remain poorly understood. From evidence of reproductive suppression, eviction, and infanticide, it is clear that social dominance plays a key role in female competition. What remains unclear, however, are the factors that influence which females become dominant. This project examines the proximal endocrine, social, and olfactory mechanisms that contribute to rank acquisition and reproductive skew in the cooperatively breeding meerkat of the South African Kalahari Desert. Using an integrated approach that combines hormonal, morphological, behavioral, and chemical analyses, this project will chart the developmental trajectory of female meerkats from conception to post dispersal, spanning three life stages (the fetal period, juvenility, and adulthood). It will examine the factors that are normally associated with acquisition and expression of female dominance and will test if female 'masculinization' through prenatal androgen exposure influences those factors. Integrating the information obtained across measures, life stages, treatment groups, and long-term ecological data will provide valuable insight into the development, maintenance, and signaling mechanisms of social and reproductive inequity to potentially reveal a novel mechanism in the evolution of cooperation and female reproductive skew. The project's broader impacts derive from (1) training undergraduates, graduates, and postdoctoral associates, especially from underrepresented groups, (2) fostering interdepartmental and international collaborations, and (3) increasing education and public awareness. The latter will be achieved by involving all team members in the communication and dissemination of scientific findings, partnering with Earthwatch, contributing new information to documentaries and websites (Friends of the Kalahari Meerkat Project) aimed for the general public, schools, and researchers, and contributing to and expanding participation in field courses.
