The ability of individuals to assess population density influences the evolution of emigration propensity and dispersal distance

Authored by Hans Joachim Poethke, Thomas Hovestadt, Andreas Gros

Date Published: 2011

DOI: 10.1016/j.jtbi.2011.05.012

Sponsors: European Union German Research Foundation (Deutsche Forschungsgemeinschaft, DFG)

Platforms: No platforms listed

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

We analyze the simultaneous evolution of emigration and settlement decisions for actively dispersing species differing in their ability to assess population density. Using an individual-based model we simulate dispersal as a multi-step (patch to patch) movement in a world consisting of habitat patches surrounded by a hostile matrix. Each such step is associated with the same mortality risk. Our simulations show that individuals following an informed strategy, where emigration (and settlement) probability depends on local population density, evolve a lower (natal) emigration propensity but disperse over significantly larger distances - i.e. postpone settlement longer - than individuals performing density-independent emigration. This holds especially when variation in environmental conditions is spatially correlated. Both effects can be traced to the informed individuals' ability to better exploit existing heterogeneity in reproductive chances. Yet, already moderate distance-dependent dispersal costs prevent the evolution of multi-step (long-distance) dispersal, irrespective of the dispersal strategy. (C) 2011 Elsevier Ltd. All rights reserved.

Tags

Competition Seed dispersal Landscapes Habitat selection Plants Patchy environments Spatially-structured populations Size-dependent dispersal Metapopulation survival Local-density