Rubenstein-Sundaresan Doctoral Dissertation Improvement Grant
Individual Behavior and Female Associations in Fission-Fusion Equid Societies
Animal societies result from the sum of all relationships that develop among individuals within populations. Many studies have demonstrated how environmental circumstances, both ecological and social, influence the benefits and costs associated with the various behavioral options available to individuals and thus how they these factors structure animal societies. Yet in species where potential relationships are many and those that form are fluid, the link between environmental features and the relationships that develop are poorly understood. This project explores how ecological features, such as the distribution of food, water and predator-free sites, together with the demographic and social features, such as population density and sex ratio, shape individual relationships in the Grevy's zebra and wild ass, two evolutionarily closely related species exhibiting 'fissioning' and 'fusing' social systems. We have developed a novel model that predicts rules for the formation and breakdown of relationships in such 'open-membership' societies and forecasts the impact these rules will have on population-wide social patterns and processes. Data will be gathered on two endangered equid species, Grevy's zebra and Onagers, from four sites. The four sites provide natural variation in the key environmental and social forces and will serve as an ideal system for testing the predictions of our model. The study will also provide useful information needed to improve conservation strategies for these species by educating students and the local populace and by demonstrating to natural resource managers how fundamental behavioral research can assist in designing effective management plans.
