Matrix quality and disturbance frequency drive evolution of species behavior at habitat boundaries.

Amanda E Martin,Lenore Fahrig

doi:10.1002/ece3.1841

Abstract

Previous theoretical studies suggest that a species' landscape should influence the evolution of its dispersal characteristics, because landscape structure affects the costs and benefits of dispersal. However, these studies have not considered the evolution of boundary crossing, that is, the tendency of animals to cross from habitat to nonhabitat ("matrix"). It is important to understand this dispersal behavior, because of its effects on the probability of population persistence. Boundary-crossing behavior drives the rate of interaction with matrix, and thus, it influences the rate of movement among populations and the risk of dispersal mortality. We used an individual-based, spatially explicit model to simulate the evolution of boundary crossing in response to landscape structure. Our simulations predict higher evolved probabilities of boundary crossing in landscapes with more habitat, less fragmented habitat, higher-quality matrix, and more frequent disturbances (i.e., fewer generations between local population extinction events). Unexpectedly, our simulations also suggest that matrix quality and disturbance frequency have much stronger effects on the evolution of boundary crossing than either habitat amount or habitat fragmentation. Our results suggest that boundary-crossing responses are most affected by the costs of dispersal through matrix and the benefits of escaping local extinction events. Evolution of optimal behavior at habitat boundaries in response to the landscape may have implications for species in human-altered landscapes, because this behavior may become suboptimal if the landscape changes faster than the species' evolutionary response to that change. Understanding how matrix quality and habitat disturbance drive evolution of behavior at boundaries, and how this in turn influences the extinction risk of species in human-altered landscapes should help us identify species of conservation concern and target them for management.

Highlights

Dispersal among habitat patches has both costs and benefits, and the effects of these on fitness should drive evolution of dispersal characteristics that minimize the cost: benefit ratio
Ecology and Evolution published by John Wiley & Sons Ltd
The evolution of boundary crossing was largely driven by matrix quality and habitat disturbance; the %SS for matrix quality was more than three times the %SS for either habitat amount or fragmentation, and the %SS for disturbance frequency was more than six times the %SS for either habitat amount or fragmentation (Table 1)

Summary

Introduction

Dispersal among habitat patches has both costs and benefits, and the effects of these on fitness should drive evolution of dispersal characteristics that minimize the cost: benefit ratio. Even if the individual survives, the energy expended during dispersal may compromise its fitness (Baker and Rao 2004; Bonte et al 2012). The primary benefits of dispersal are that it allows individuals to track available resources and escape declining local conditions (Tellerıa and Perez-Tris 2003). The attributes of a species’ landscape should influence the evolution of dispersal characteristics. In landscapes with less habitat, the costs of dispersal should be higher because individuals will spend more time in the matrix (Baker and Rao 2004; Johnson et al 2009).

Methods

Results

Discussion

Conclusion