Doctoral Dissertation Improvement: Male-immature relationships in the mountain gorilla (Gorilla beringei beringei)

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

The purpose of this project is to understand the proximate mechanisms, form, and evolutionary function(s) of social relationships between adult male and immature mountain gorillas (Gorilla beringei beringei). The project will address four primary questions: 1) are male and immature gorillas capable of distinguishing paternal kin from non-kin? 2) are such relationships hormonally mediated, specifically through testosterone and prolactin? 3) how do male-immature relationships change over time as immatures grow? and 4) is there evidence to support alternative hypotheses about the function of these relationships? Behavioral observations will be conducted on at least four groups of habituated gorillas living in Parc des Volcans, Rwanda, and monitored by the Karisoke Research Center. Adult males and immatures will be followed four days per week, and all relevant behaviors recorded. Hormonal data will be collected using non-invasive methods, specifically collection of urine samples from adult males and collection of fecal samples from males, mothers, and immatures. Hormones will be extracted from the samples in Rwanda before being shipped to the Lincoln Park Zoo in Chicago, Illinois for analysis. The role of fathers is variable across non-human primate species, but to date little research has been conducted on non-monogamous species and great apes. Mountain gorillas are an interesting study species because of their highly flexible social structure, which includes both multi and single-male groups, and therefore bears similarities to variability in human mating systems. This project will give us insight into the origins of paternal behavior in different mating systems and the implications it has for offspring, in both the short and long term. This award will provide support to enable a promising student to establish a strong independent research career.