FEMALE PREFERENCE FOR DYNAMIC TRAITS IN THE GREEN SWORDTAIL, XIPHOPHORUS-HELLERI

Analyses of the relationship between female preference and male behavi our have been complicated by correlated variation in factors such as m ale size and appearance. This study examined the effects of systematic ally manipulating male behaviour, while holding male morphology consta nt. Female green swordtails were shown video-recorded sequences of the same male engaging in an active courtship display, performing similar levels of feeding activity, and remaining inactive. Control sequences of moving food particles and of an empty aquarium were also presented . Female responsiveness was significantly different across time interv als (before, during and after the stimulus) for the three stimuli show ing a male, but not for the two controls. Analyses of female behaviour patterns during the stimulus presentations revealed that they preferr ed sequences of courting males to all other stimuli. Females did not r espond differently to the feeding and inactive sequences. These result s indicate that female interest depends upon a specific set of motor p atterns, and suggest thar male behaviour and morphology may act synerg istically to determine female preference. Video stimuli should prove u seful in future experiments seeking to identify the role of specific c ourtship motor patterns in mate choice. (C) 1996 The Association for t he Study of Animal Behaviour