A game theoretical approach to conspecific brood parasitism

Abstract

We constructed a game theoretical model to predict optimal patterns of egg laying in systems where individuals lay in the nests of others as well as in their own nests. We show that decreasing the effect of position within an egg-laying sequence on the worth of an egg should lead to reduced parasitism. Indeed, parasitism can only flourish if the worth of an egg to its biological parent declines with the total number of eggs laid in that nest. Further, we found that increasing the intrinsic costs of egg production should lead to an increased propensity for conspecific brood parasitism. The model also predicts that variation in hosts' ability to reject parasitic eggs has little effect on parasitism until this ability is well developed.