The effects of food competition on energetics and population dynamics

Food is necessary to survive and reproduce. In food-limited environments, competition among individuals leads to energy shortfalls, not just via lack of food, but also due to stress associated with feeding competition. Whereas previous primate research has focused on the effects of food competition among individuals, this research asks whether competition between groups exerts similar effects on indicators of physiological well-being.

The project uses a socio-ecological framework to pinpoint what features of local environments make some groups more versus less vulnerable to the effects of food competition. The project involves extensive training and mentoring of students from groups under-represented in biological anthropology through lab work, data analysis, and dissemination of results in conference presentations and journal articles.

It also involves the development of instructional videos on laboratory methods that will be used to assist students in lab classes.

To understand the effects of within- versus between-group food competition, this project focuses on the behavior and energetics of two primate populations whose group sizes are inversely correlated. The research (1) tracks the day-to-day energetic conditions of individuals using metabolic hormones, (2) disentangles the energetic effects of competition among individuals, groups, and species, and (3) evaluates the costs of competition on short-term reproductive status, measured through ovarian hormones.

This project can serve as a model for future studies of community-wide feeding competition – particularly among long-lived, dietarily flexible species – and initiate consideration of how between-group and between-species dynamics affect competitive regimes within species.

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.