The time P. mexicana males spent associating with one of the two females in simultaneous choice tests (A conspecific vs P. formosa stimulus females; B large vs small conspecific females). During the first part the male was alone in the test tank, during the second part an audience male was visually presented. In treatment 1 a conspecific male was used as audience male, in treatment 2 no audience male was presented (“control”), and in treatment 3, a swordtail male was the audience. Gray bars indicate time spent near the initially preferred female, open bars indicate time spent near the initially non-preferred female.1