Spatially explicit ecological models: population consequences of individual habitat selection mechanisms

Organisms that occupy a single territory for their entire adult lifetime must choose as juve­niles the location that will determine their lifetime reproductive success. However, juveniles will not normally have global information about the location of high quality, unoccupied habitat. They may only know the quality of the habitat tl1at they are currently moving through, and possibly have knowledge, or an estimate, of the distribution of habitat quality. In addition, there is usually an elevated risk of mortal­ity during dispersal, which increases the incentive to choose a territory quickly. There are many possi­ble ways in which this problem, which is a particular instance of the "job search" problem, could be solved by organisms. In this paper we examine the population consequences of several individual habi­tat selection mechanisms. We use an individual based, spatially explicit population model of the Greater Glider, Petauroides volans. We examine six different dispersal strategies which vary the scale at which individuals sample the landscape, and how choosy they are about the habitat they settle in. The dispersal strategy has a strong effect on the size of the equilibrium population. However, the strategy that achieves the highest population sizes is not evolutionarily stable.