Timid Consumers: Self-Extinction Due to Adaptive Change in Foraging and Anti-predator Effort

Timid Consumers: Self-Extinction Due to Adaptive Change in Foraging and Anti-predator Effort Original Research Article Pages 76-91 Matsuda H., Abrams P. A. Close preview | Purchase PDF (666 K) | Related articles | Related reference work articles Abstract Abstract We model the evolution of anti-predator ability in a prey species whose predator has a saturating functional response. Increased anti-predator ability is assumed to require decreased food intake. The anti-predator ability is specified by the value of a continuous trait, whose evolutionary dynamics are determined by the rate of change of fitness as a function of the trait value. This situation can produce a perpetual evolutionary increase in the anti-predator trait, with a concomitant decrease in foraging (or other fitness-enhancing activities); the end result of the process is often extinction of the prey species. This outcome is most likely if the predator population size is maintained by some alternative prey species. Conditions that can promote or counteract this tendency toward self-extinction are discussed.