Bowerbirds’ Mate-Selection Contests

In the world of satin bowerbirds, the male-birds engage in a contest among themselves to win their mates: they spend considerable time and effort in decorating their own bowers, and then attempt to destroy the decorations of their rivals’ bowers. The female-birds, in turn, select their mates on the basis of the attractiveness of the best surviving bowers. We study a game-theoretic model of such a mating contest, where two male-birds of distinct strengths engage in competitive signaling with value-less signals followed by signal sabotage (in an environment where a female-bird infers a male-bird’s strength by observing the quality of his surviving bower). We prove that sabotage possibilities can improve the outcomes for both male-birds – since anticipated threat of sabotage depresses each male-bird’s incentive to engage in costly signaling, while harming the outcome for the female-bird – as sabotage introduces noise in the female-bird’s selection process.