BEHAVIORAL DYNAMICS OF TWO INTERACTING HAWK–DOVE POPULATIONS

We present a model of two interacting populations using two individual strategies, hawk and dove. Individuals encounter each other frequently and can change tactics several times in their life. Conflicts occur between individuals belonging to the same population and to different populations. The general model is based on the replicator equations which are used to describe the variations of the hawk proportions of the two populations. According to parameter values, namely the gain-, the intra- and inter-population costs, and the relative intra-population encounter rates, we classify the different phase portraits. We show that a decrease in the intra-population cost of a population provokes an increase in the hawk proportion in this population and of the dove proportion in the other population. An increase in the inter-population cost favors hawk strategy in the population which causes more injuries and dove strategy in the other. We also study the effects of the relative densities of the two populations on,the stability of equilibria. In most cases, an increase in the relative density of a population leads to a decrease in hawk proportion in this population and of dove proportion in the other.