title: The ability of individuals to assess population density influences the evolution of emigration propensity and dispersal distance.
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.
authors: University of Würzburg, Field Station Fabrikschleichach, Glashüttenstrasse 5, 96181 Rauhenebrach, Germany. poethke@biozentrum.uni-wuerzburg.de
authors: Hans Joachim
authors: HJ
authors: Poethke
authors: Andreas
authors: A
authors: Gros
authors: Thomas
authors: T
authors: Hovestadt