Doctoral Dissertation Research: Examining causes and consequences of variation in male reproductive success in wild primates

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

In nonhuman primates a range of male behaviors are observed that relate to male success in siring offspring. This doctoral dissertation research project examines reproductive payoffs of different male strategies (aggressive versus affiliative) in wild geladas (primates). Results from this study provide valuable insights about the evolution of male reproductive strategies and will enhance understanding about the adaptive significance of male-female social bonds in a long-lived primate species. While conducting the proposed research, the doctoral student will continue to work with K-12 students from underrepresented communities to foster excitement about science and research and give talks about primate behavior and evolution at local elementary schools. Additionally, the doctoral student will continue training undergraduate students in the laboratory throughout her dissertation research and mentor women from groups underrepresented in primatology. This research investigates how different male behavioral strategies affect reproductive success in geladas. Male geladas gain reproductive opportunities by becoming the dominant leader over a family of multiple females and their offspring. Male reproduction is thus a function of the number of fertile females in the group combined with how long he remains the dominant leader (tenure length). The proposed project will use long term data (collected over 13 years) in combination with detailed behavioral, hormonal, and paternity data from individually known leader males to assess which factors contribute to male reproductive success. First, the investigators will measure reproductive success by assigning paternity through genotyping all leader males and infants in the project. Second, they will quantify physical attributes that could affect reproductive success in geladas. These include: i) body size (measured through laser photogrammetry), ii) chest patch redness (measured by comparing photos of gelada chest patch against a standard color checker chart), and iii) testosterone levels using fecal samples collected from individual leader males (measured through a biotin labelled enzyme-immunoassay). Third, the investigators will assess what social strategies males employ to increase reproductive success by quantifying male-female social relationships through behavioral observations and recording the occurrence of infanticide. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.