Doctoral Dissertation Research: Costs of competing for food in wild primates

Competition between species exists nearly everywhere in nature, yet its intensity and consequences are difficult to measure. This study investigates how changes in the presence of competitors affects access to food resources, health, and reproduction in small primates. Results from this study will identify and measure the wide-ranging outcomes that small primates experience because of food-related competition. Results of this study help to explain the behavioral variation seen among primate species that live together eating similar diets, contributes to understanding population structure, and offers insight for conservation efforts for nonhuman primates. This study also provides significant training opportunities in field and laboratory methods for students from groups historically excluded from STEM internationally and the U.S. Most primates live in highly biodiverse communities and compete intensely with other species for access to food sources. Although between-species interactions are likely to have substantial effects on access to resources, primate studies have focused primarily on competitive interactions within a species. As a result, there is an urgent need to explore how between-species competition shapes reproduction, population dynamics, community structure, and even social interactions. This study examines how small-bodied red-tailed monkeys (Cercopithecus ascanius) are affected by several larger primate species, by examining variation in competitor pressure, food availability, and red-tailed monkey physical condition at four field sites. The investigators will evaluate metabolic hormones from non-invasively collected urine and fecal samples to determine when individuals are in a state of energy gain, minor deficit, or profound tissue wasting. Reproductive effort will be assessed by tracking births and measuring reproductive hormones. These results will be used to determine whether the three larger, competing primate species have similar effects on red-tailed monkey energetics and reproduction, or if some competitors are unusually detrimental to a smaller-bodied species. This project is funded jointly by Biological Anthropology and Build and Broaden programs (SBE).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.