Female resistance to male seduction in zebra finches

A recent revival of the theory of sexual conflict leads to new interest in the question of how much females control copulation. Using the zebra finch, Taeniopygia guttata, as a model, I investigated the mechanisms with which males tried to persuade females to copulate with them. Analysing the outcome of a large number of experimental male-female encounters, I concluded that apart from some effect of male choosiness (preference for certain females), females were fully in control of copulation. Males did not differ in their abilities to overcome female resistance, either in terms of sensory exploitation (variation in ornamentation and display) or coercion (use of aggression). Variation in beak colour had no influence on male mating success, but male song rate may be a sexually selected trait: males that sang more frequently obtained more copulations, but this was because other males missed opportunities by not even attempting to display to females. Whenever a male started displaying, female responsiveness, and hence male copulatory success, was not influenced by how persistently he sang. These findings support a theory of chase-away sexual selection, rather than a good-genes theory, which has typically been invoked to explain variation in male song rate. Between-individual differences in male song rate may reflect alternative reproductive strategies (mating effort versus parental effort) rather than variation in male quality. Finally, I found marked differences in sexual responsiveness between females, which is not anticipated by current models of sexual selection and hence urges further investigation. (C) 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.