Predator interference emerging from trophotaxis in predator-prey systems: An individual-based approach
Authored by Yuri Tyutyunov, Lyudmila Titova, Roger Arditi
Date Published: 2008
DOI: 10.1016/j.ecocom.2007.09.001
Sponsors:
French National Institute for Agricultural Research (INRA)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
An individual-based model describing predator-prey interactions within a
closed rectangular habitat was developed to study how different
assumptions about the individual movements lead to the emergence at the
population level of various kinds of prey- and predator-dependence in
the spatially aggregated trophic function.
In addition to random walk, both species are capable of directional
movement, i.e., the model accounts for the predator prey-taxis and
evasion of predators by prey individuals. The taxis stimulus of each
species is the odour of the other species, which is distributed
continuously in space. Spatial behaviour of individuals is determined by
the specific response to the odour gradient and the tendency to maintain
the taxis velocity. In order to facilitate the assessment of the trophic
function, the model allows removing the effect of demographic density
variations on the predator ration, keeping population sizes constant.
Analyzing the dependence of the trophic function with the average
predator density, we found that, depending on the intensity of taxis, the predator population exhibits various degrees of interference, from
very low to very high values. In particular, a moderate taxis generates
distinct levels of interference including the ratio-dependent case. The
letter maximizes the average consumption rate.
A new generalized function containing ratio-dependence and
prey-dependence as special cases, at high and low population abundances, is suggested. This trophic function fits the simulated data better than
the Hassell-Varley-Holling expression does. (C)2007 Elsevier B.V. All
rights reserved.
Tags
models
Dynamics
Heterogeneity
ideal free distribution
Functional-response
Biological-control
Exploitation ecosystems
Ratio-dependent predation
Mutual interference
Resource enrichment