LTREB RENEWAL: Fitness consequences of pleiotropic androgen effects in free-living mammals

Michigan State University, East Lansing MI

Investigators

Abstract

Current understanding of the long-term effects of prenatal hormone exposure on offspring fitness in natural populations is extremely limited, particularly in viviparous species. The proposed research investigates the fitness consequences of prenatal androgen exposure in a long-lived mammalian carnivore, the spotted hyena. Wild hyenas are studied in Kenya to document correlates and consequences of naturally-occurring variation in early androgen exposure. Cubs born to mothers with known concentrations of androgens during pregnancy are followed into adulthood to test a hypothesis suggesting that androgen-induced variation in cub behavior and morphology is associated with variation in fitness. Two other competing hypotheses are also evaluated, each suggesting different extents to which opposing hormone effects might constrain adaptive evolution. This work will permit uniquely integrated study in long-lived mammals of the development of hormonally-induced traits, from their induction in the womb to their consequences in natural populations. It will be important for understanding more broadly the role of prenatal androgen exposure in the generation of variation in behavior and morphology, and the role played by androgens in the evolution of mammalian life histories. This research crosses disciplinary boundaries and offers unique and highly valuable international training opportunities for American students. The work also trains Kenyan students, and supports Masai students in local elementary schools near the study site. In addition, project personnel work closely with the public media in the USA and abroad, maintain an educational website, and give many lectures each year to lay audiences. Finally, via a web portal this research makes available to other researchers and the general public core data tables in a database that documents hyena behavior, demography, and physiology at the study site since 1988. This project is jointly supported by the Animal Behavior Program and International Science and Engineering.