Species that are subject to predation or parasitism must balance the conflicting demands of escaping from their predators/parasites while still competing for limited resources. Physical attributes of habitats may affect the ability of species to balance these demands, but this possibility remains unexplored. The goal of this project is to examine how habitat structural complexity modifies the ability of host ants to escape from their specialist parasitoids while still competing effectively for resources. By using hosts that differ in their competitive ability within the ant community, we will also explore whether consequences of habitat complexity for host-parasitoid interactions depend on host dominance level. Experiments will be implemented on ant colonies in the field using portable foraging bins to manipulate levels of habitat complexity (leaf litter), competition and parasitism. Habitat complexity provides refuge for prey, and in doing so, may allow prey to escape from predators/parasites but still compete effectively. However, disturbance events such as fire and grazing that are common in the Southwestern United States alter habitat complexity. Such disturbance events therefore have the potential to affect the composition of natural communities by modifying species interactions. Not only will this project be conducted in the context of an initiative to preserve Chihuahuan desert lands along the U.S.-Mexican border, it will also provide valuable training for biology students from both U.S. and Mexican institutions.
