Body length and body colour scores of males used in Experiment 1.

Mean ± SE total body length (mm) and body colour score (proportion of left side of body covered with black and orange colours) of focal male guppies and the paired stimulus males categorized as relatively more attractive (MA) and less attractive (LA) used in each treatment of laboratory Experiment 1. The body length and colour scores of paired stimulus males in each treatment were separately compared with the paired t-test. N denotes the number of replicated trials in each treatment.