The Evolution of Reliable and Unreliable Badges of Fighting Ability

SYNOPSIS. When a population may be characterized by interferencecompetition for resources, variation in fighting ability amongindividuals, and repeated confrontations between individuals,together with difficulty of individual recognition, badges ofstatus should invade as recognition marks that render good fightersmemorable. Reliability of such badges can be maintained by negativefrequency-dependent selection when individuals of differentappearance (and status) either play mutually beneficial rolesor employ alternate competitive tactics. In territorial socialsystems intraspecific mimicry of recognition badges should evolvebecause, in contrast to group-living situations, the cost toa cheat of being discovered is low when individuals are dispersed.The general result of such mimicry is that good and poor fightersbecome similar in appearance. From the theoretical treatmentof status recognition badges I derive a number of predictionsthat pertain both to interand intraspecific differences in conspicuouscoloration and to the evolution of local song dialects in birds.