Analysis of adaptive foraging in an intraguild predation system

Abstract

An intraguild predation (IGP) system with adaptive foraging behavior was analyzed using a simple mathematical model. The main aim was to explore how the adaptive behavior affects species interactions as well as how such interactions derived from adaptive behavior affect community stability. The focal system contained top predators, intermediate predators, and basal prey. Intermediate predators exhibit antipredator behavior and balance costs (e.g. perceived predation risk) and benefits (e.g. resource intake) to determine their foraging effort. Density-dependent foraging behavior with the unique connectance of the IGP food web created unusual species interactions. Notably, increased prey density can transmit negative indirect effects to top predators while increased top predator density transmits positive indirect effects to prey population. The nature of these interactions is density-dependent. The results suggest that both IGP (as opposed to linear food chain) and adaptive foraging behaviors may strongly influence community dynamics due to emergent interactions among direct effects and indirect effects. Furthermore, the adaptive foraging of intermediate predators may stabilize the community as a whole

Adaptive behaviour, tri-trophic food-web stability and damping of chaos

“…Namely that provided intra-guild predation is a feasible trophic mode and there exists an optimal foraging effort for the intra-guild prey, adaptive behaviour will always drive the system towards stability (although whether stability is actually reached is not assured). It is noteworthy that while the adaptive behaviour of the omnivore exerts some control on the stability of tri-trophic systems [28], our results and others [29,30] suggest that the adaptive behaviour of the seemingly most vulnerable member of the tri-trophic food web exerts a strong control on the dynamics of such systems. The underlying mechanism appears to be the ability of adaptive behaviour to buffer the system from rapid fluctuations, damping out largeamplitude oscillations and bringing a semblance of stability to the system.…”

“…For instance, the effect of adaptive behaviour has been shown to stabilize linear food chains [22] and to promote the coexistence of competing predators [23] and prey [24] and have a general stabilizing effect on food webs [25][26][27]. With regard to intra-guild predation, adaptive, fitness-seeking behaviour of intra-guild predator yields a relatively small effect in facilitating coexistence [28], whereas the effect of adaptive behaviour of the intra-guild prey appears to be more pronounced [29,30].…”

Intraguild Interactions

“…In the complex of Col. maculata , Har. Nevertheless, predator facilitation may be rare in the fi eld, since three key elements are required for this interaction: other interactions such as cannibalism, of a temporal sequence of predators, of refuges, of anti -predatory mechanisms, or others (Okuyama & Ruyle 2003, Kindlmann & Houdkova 2006, Amarasekare 2007, Borer et al 2007, Holt & Huxel 2007, Janssen et al 2007, Rudolf 2007. Nevertheless, predator facilitation may be rare in the fi eld, since three key elements are required for this interaction: other interactions such as cannibalism, of a temporal sequence of predators, of refuges, of anti -predatory mechanisms, or others (Okuyama & Ruyle 2003, Kindlmann & Houdkova 2006, Amarasekare 2007, Borer et al 2007, Holt & Huxel 2007, Janssen et al 2007, Rudolf 2007.…”

Influence of predator-specific defense adaptation on intraguild predation

“…phenotypic plasticity or evolution) is now recognized as a major ecological factor that significantly influences population and thus community dynamics in ways that can facilitate species coexistence (Abrams 2000, Bolker et al 2003, Werner and Peacor 2003, Hairston et al 2005). This potential coexistence facilitation mechanism has been increasingly incorporated into IGP studies (foraging adaptation of IG predator; Křivan 2000, Křivan and Diehl 2005, foraging‐defense adaptation by IG prey; Okuyama and Ruyle 2003, defense adaptation by basal prey; Kimbrell et al 2007).…”