PARENT SESSION
Oral Session # 10: Predator-Prey Ecology I: Terrestrial I: Theory and Cues.
Presiding: A Liebold
Monday, August 4. 8:00 AM to 11:30 AM, SITCC Meeting Room 202.

Evolution, predator switching, and population stability: An individual-based approach.

Kimbrell, Tristan^*,1, Holt, Robert¹, ¹ University of Florida, Gainesville, FL, USA

ABSTRACT- Predator switching has traditionally been viewed as a stabilizing mechanism in multispecies communities. However, recent models have suggested that predator switching may destabilize population dynamics and even lead to species extinction. Most of this work has been based on the elaboration of standard predator-prey models represented as systems of differential equations. We examined the dynamical and evolutionary implications of predator switching using a spatially-explicit, individual-based model, in which switching involved movement between two habitat patches. We compared three different predator types: predators that randomly moved between patches, predators that optimally switched between patches, and predators with incomplete information that sampled the patches and used a memory rule to determine when to switch patches. We first explored how each switching strategy impacted population dynamics. We then allowed alternative switching strategies to compete, and examined the potential for sustained coexistence of alternative switching strategies. Evolution was incorporated by adding a mutation rule for the switch decision variable. An adaptive dynamics approach suggests that switching strategies that are allowed to evolve often result in population dynamics that are more stable than non-evolving strategies.

Key words: individual-based model, persistence, predator switching, spatially-explicit