The conformation of a female preference for a composite male trait in green swordtails

Female green swordtails, Xiphophorus helleri, possess a preference for the multicomponent male sword. Previous work suggests that this female preference is a result of a pre-existing receiver bias favouring a sword and has contributed to sword evolution via intersexual selection. We use video presentations to investigate how females respond to components of this composite trait. Complete swords in this species have at least four individual components. Based on female response to video stimuli depicting males with intact swords and males in which sword components were digitally manipulated, it appears that males possessing complete swords elicit the strongest female response. Additionally, we found that females prefer stimuli with black sword coloration to those lacking black coloration. The results suggest that multiple components of the sword stimulate females, and that these components operate in conjunction to make the sword structure more attractive to females. 2002 The Association for the Study of Animal Behaviour.