title: Remarks on antipredator behavior and food chain dynamics.
abstract: When consumers feeding on a resource spend time in avoiding high risks of predation, the predator functional response declines with predator density. While this is well established, less attention has been paid to the dependence of the consumer functional response on predator density. Here we show how the separation of behavioral and ecological timescales allows one to determine both responses starting from an explicit behavioral model. Within the general set-up considered in this paper, the two functional responses can tend toward Holling type II responses when consumers react only weakly to predation. Thus, the main characteristics of the standard Rosenzweig-MacArthur tritrophic food chain (logistic resource and Holling type II consumer and predator) remain valid also when consumers have weak antipredator behavior. Moreover, through numerical analysis, we show that in a particular but interesting case pronounced antipredator behaviors stabilize the system.
authors.affiliation: CIRITA, c/o Department of Electronics and Information, Politecnico di Milano, Via Ponzio 34/5, 20133 Milano, Italy. rinaldi@elet.polimi.it
authors.forename: Sergio
authors.initials: S
authors.lastname: Rinaldi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Gragnani
authors.forename: Silvia
authors.initials: S
authors.lastname: De Monte
mesh_terms: D000818:Animals; D020387:Food Chain; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D011235:Predatory Behavior