CONTEXT AND CONSEQUENCES OF COMB DISPLAYS BY MALE ROCK PTARMIGAN

Male rock ptarmigan, Lagopus mutus, display their supraorbital combs for about 50% of the time during both inter- and intra-sexual interactions in the breeding season, but rarely when they are alone. During three seasons in the Canadian high arctic, mating success of male rock ptarmigan was positively correlated with both comb condition and previous breeding experience. There was no general relationship between a male's comb size and his mating success, contrary to results obtained in both a previous study in this same population and experimental studies on other species with combs. There was, however, a correlation between comb size and mating success among inexperienced males that may explain the results from other studies. Model presentation experiments also revealed significant relationships between comb condition, comb size and aggressiveness, such that males with smaller combs or combs in poor condition were less likely to attack male models with artificial combs. The size of model combs, however, had no influence on male aggressiveness. Because combs are frequently attacked during male x male interactions, the condition of these ornaments may honestly advertise male fighting ability and as a result may be an important criterion for female choice. © 1993 The Association for the Study of Animal Behaviour. All rights reserved.