HABITAT SELECTION AS AN EVOLUTIONARY GAME

Under habitat selection, mobile foragers may not only possess behavioral flexibility that allows them to utilize habitats selectively or opportunistically, but they may also possess heritable traits that influence their performance within each habitat. A game theoretic model is developed that investigates this evolutionary dimension of habitat selection. The model follows that of Rosenzweig (1987b) and considers a patchy environment containing two distinct habitat types. Behaviorally, foragers may be selective or opportunistic; morphologically, foragers possess traits that represent a trade-off between performance in the two habitat types. Depending on the environment's structure, one of three types of communities emerges as the ESS: (1) a single generalist species that behaves opportunistically, (2) two species that are extreme specialists on habitat 1 and 2, respectively; behaviorally, these species are selective on their respective habitat types, and (3) one generalist species that behaves opportunistically and one specialist species that behaves selectively on its preferred habitat. Community (1) emerges when habitat selection is costly, community (2) emerges when habitat selection is cost-free, and community (3) emerges when the relative abundances or productivities of the two habitat types are lopsided.