Figure 1.

Mating duration responses of two strains of Drosophila melanogaster (Canton‐S and Dahomey wild types) with wild‐type females of their own strain, following simulated or actual exposure to visual cues of competition from conspecific rivals. Males of each strain were held singly in vials against a mirror with the reflective side up (“single males plus mirrors,” to simulate the presence of a conspecific rival through visual cues) or down (“single males” control) or paired with a conspecific male (“paired males”)