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Evolution of predator dispersal in relation to spatio-temporal prey dynamics: how not to get stuck in the wrong place!

Travis JM, Palmer SC, Coyne S, Millon A, Lambin X - PLoS ONE (2013)

Bottom Line: We additionally demonstrate that the cost of dispersal can vary substantially across space and time.Perhaps as a consequence of current environmental change, many key prey species are currently exhibiting major shifts in their spatio-temporal dynamics.By exploring similar shifts in silico, we predict that predator populations will be most vulnerable when prey dynamics shift from stable to complex.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK. justin.travis@abdn.ac.uk

ABSTRACT
The eco-evolutionary dynamics of dispersal are recognised as key in determining the responses of populations to environmental changes. Here, by developing a novel modelling approach, we show that predators are likely to have evolved to emigrate more often and become more selective over their destination patch when their prey species exhibit spatio-temporally complex dynamics. We additionally demonstrate that the cost of dispersal can vary substantially across space and time. Perhaps as a consequence of current environmental change, many key prey species are currently exhibiting major shifts in their spatio-temporal dynamics. By exploring similar shifts in silico, we predict that predator populations will be most vulnerable when prey dynamics shift from stable to complex. The more sophisticated dispersal rules, and greater variance therein, that evolve under complex dynamics will enable persistence across a broader range of prey dynamics than the rules which evolve under relatively stable prey conditions.

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Related in: MedlinePlus

Evolution of a more complex predator dispersal strategy.A qualitatively similar response of dispersal to varying prey r is observed when predators can take multiple steps and evolve a stopping rule dependent on prey density. (A) Dispersal probability at seven levels of predator per-step dispersal mortality cstep. (B) The mean number of steps taken by predators across the same range of r and cstep as in (A). The number of steps taken by predators is a function of the rules that they have evolved, together with the spatio-temporal characteristics of the environment. (C) The mean stopping rules that evolve for a range of prey r at a moderate per-step mortality (cstep = 0.02). The ‘slope’ gene determines the ‘steepness’ of the stopping threshold (the rate of change of probability with increasing prey density), and the ‘slope’ and ‘intercept’ genes together control the position of the stopping threshold in relation to prey density.
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pone-0054453-g002: Evolution of a more complex predator dispersal strategy.A qualitatively similar response of dispersal to varying prey r is observed when predators can take multiple steps and evolve a stopping rule dependent on prey density. (A) Dispersal probability at seven levels of predator per-step dispersal mortality cstep. (B) The mean number of steps taken by predators across the same range of r and cstep as in (A). The number of steps taken by predators is a function of the rules that they have evolved, together with the spatio-temporal characteristics of the environment. (C) The mean stopping rules that evolve for a range of prey r at a moderate per-step mortality (cstep = 0.02). The ‘slope’ gene determines the ‘steepness’ of the stopping threshold (the rate of change of probability with increasing prey density), and the ‘slope’ and ‘intercept’ genes together control the position of the stopping threshold in relation to prey density.

Mentions: Where reaction norms that determine immigration rules were allowed to evolve jointly with emigration rate, we observed qualitatively similar responses of evolved emigration probability to the prey dynamics; this was true regardless of whether the predators stopped as a function of prey density alone (Fig. 2A) or as a function of the ratio between prey and predator density (data not shown). Interestingly, in simulations with a high per-step mortality cost of dispersal, we observed a sustained increase in emigration probability between r = 2.5 and r = 4.0. This is in contrast to results for lower costs where almost all individuals emigrated under more complex prey dynamics.


Evolution of predator dispersal in relation to spatio-temporal prey dynamics: how not to get stuck in the wrong place!

Travis JM, Palmer SC, Coyne S, Millon A, Lambin X - PLoS ONE (2013)

Evolution of a more complex predator dispersal strategy.A qualitatively similar response of dispersal to varying prey r is observed when predators can take multiple steps and evolve a stopping rule dependent on prey density. (A) Dispersal probability at seven levels of predator per-step dispersal mortality cstep. (B) The mean number of steps taken by predators across the same range of r and cstep as in (A). The number of steps taken by predators is a function of the rules that they have evolved, together with the spatio-temporal characteristics of the environment. (C) The mean stopping rules that evolve for a range of prey r at a moderate per-step mortality (cstep = 0.02). The ‘slope’ gene determines the ‘steepness’ of the stopping threshold (the rate of change of probability with increasing prey density), and the ‘slope’ and ‘intercept’ genes together control the position of the stopping threshold in relation to prey density.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3569443&req=5

pone-0054453-g002: Evolution of a more complex predator dispersal strategy.A qualitatively similar response of dispersal to varying prey r is observed when predators can take multiple steps and evolve a stopping rule dependent on prey density. (A) Dispersal probability at seven levels of predator per-step dispersal mortality cstep. (B) The mean number of steps taken by predators across the same range of r and cstep as in (A). The number of steps taken by predators is a function of the rules that they have evolved, together with the spatio-temporal characteristics of the environment. (C) The mean stopping rules that evolve for a range of prey r at a moderate per-step mortality (cstep = 0.02). The ‘slope’ gene determines the ‘steepness’ of the stopping threshold (the rate of change of probability with increasing prey density), and the ‘slope’ and ‘intercept’ genes together control the position of the stopping threshold in relation to prey density.
Mentions: Where reaction norms that determine immigration rules were allowed to evolve jointly with emigration rate, we observed qualitatively similar responses of evolved emigration probability to the prey dynamics; this was true regardless of whether the predators stopped as a function of prey density alone (Fig. 2A) or as a function of the ratio between prey and predator density (data not shown). Interestingly, in simulations with a high per-step mortality cost of dispersal, we observed a sustained increase in emigration probability between r = 2.5 and r = 4.0. This is in contrast to results for lower costs where almost all individuals emigrated under more complex prey dynamics.

Bottom Line: We additionally demonstrate that the cost of dispersal can vary substantially across space and time.Perhaps as a consequence of current environmental change, many key prey species are currently exhibiting major shifts in their spatio-temporal dynamics.By exploring similar shifts in silico, we predict that predator populations will be most vulnerable when prey dynamics shift from stable to complex.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK. justin.travis@abdn.ac.uk

ABSTRACT
The eco-evolutionary dynamics of dispersal are recognised as key in determining the responses of populations to environmental changes. Here, by developing a novel modelling approach, we show that predators are likely to have evolved to emigrate more often and become more selective over their destination patch when their prey species exhibit spatio-temporally complex dynamics. We additionally demonstrate that the cost of dispersal can vary substantially across space and time. Perhaps as a consequence of current environmental change, many key prey species are currently exhibiting major shifts in their spatio-temporal dynamics. By exploring similar shifts in silico, we predict that predator populations will be most vulnerable when prey dynamics shift from stable to complex. The more sophisticated dispersal rules, and greater variance therein, that evolve under complex dynamics will enable persistence across a broader range of prey dynamics than the rules which evolve under relatively stable prey conditions.

Show MeSH
Related in: MedlinePlus