Doctoral Dissertation Research: Wild primate responses to variation in feeding habitat quality

Arizona State University, Scottsdale AZ

Investigators

Abstract

Shifts in habitat likely served as powerful drivers throughout human evolution. While the fossil record provides evidence for physical adaptations related to changing habitats and diets, it remains unclear how the evolution of human social behavior was shaped by changes in food availability. To address this gap, non-invasive research on wild nonhuman primates can provide comparative data for reconstructing the potential behaviors of early human ancestors. This doctoral dissertation research project leverages data from a long-studied, wild nonhuman primate population that has undergone significant habitat change. The research focuses on two potential mechanisms shaping social behavior: the distribution of food in a landscape and its quality. The project promotes the progress of science by advancing our understanding of primate sociality and how major climatic shifts may have shaped human social evolution. Additionally, understanding the consequences of long-term habitat change for an endangered primate can inform conservation research and activities. The project also promotes international research collaborations, provides scientific training to undergraduate students and community members, and strengthens community relationships and promotes environmental stewardship through outreach events that highlight habitat recovery in protected landscapes. Chimpanzees show wide variation in sociality and the quality of landscapes they inhabit. Researchers suspect that differences in food availability drive chimpanzee social variation; however, research sites also differ in terms of ecology and methods, which has largely prevented studies directly comparing populations. Long-term data on one population of chimpanzees provide a unique opportunity to explore the consequences of temporal and spatial habitat variation on behavior. Systematic data collection beginning in the 1970s has captured detailed behavioral observations across six decades of significant habitat recovery from anthropogenic disturbance. Supplementing 66 community-years of existing behavioral observations and 20 years of phenology data, the researchers collect original focal follow data and non-invasive urine samples for energetic biomarker analysis. They also use historic feeding data and remote-sensed landscape metrics to construct spatial models of plant food species distribution from 1980-2020. Together, these data are analyzed to establish linkages between food availability, diet composition, individual energetic state, and behavior. The researchers also identify how food distribution influences ranging and sociality, as well as the impact of a given individual’s range quality on their ability to engage in energetically demanding social behaviors. Overall, this research expands understanding of hominin social evolution, the drivers of intraspecific behavioral differences in chimpanzees, and the behavioral consequences of habitat recovery in an endangered primate. 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.