Assessment of the quality of copulation partners in the monogamous bearded tit

Females try to control paternity in various ways. They may resist copulation attempts by males but they may also feign resistance in order to incite competition between males. In the lifetime monogamous bearded tit, Panurus biarmicus, chase-flights, both within pairs and with other males, occur during the female's fertile period. In general, these chase-flights are followed by copulations. Females in this study were able to resist copulations, but they also often approached males and solicited copulations by wing flapping; if males tried to mount the females, they resisted and flew away. During the fertile period females solicited extra-pair males to chase them significantly more often than they solicited chases with their own mate. In isolated pairs chase-flight activity was reduced and most copulations occurred without preceding chase-flights. In addition, females in isolated pairs solicited their partners to chase them significantly less often than females with extra males available. This suggests that females use chases to incite male-male competition and thus to obtain 'good genes'. In contrast to other studies, females paired to high-ranking males incited more chase-flights than females paired to low-ranking males, perhaps because only high-quality females could afford to perform this energetically expensive activity. (C) 1997 The Association for the Study of Animal Behaviour.