Fig. 2.

Phonotaxis to simultaneous and single sources under field conditions. Direct responses. Percentage of correct responses with direct approach to source one location (blue). Indirect responses. Percentage of correct responses with initial misdirected walking trajectories to a phantom source (0° heading) (green). Incorrect responses. Percentage of unsuccessful phonotaxis (red) with walking trajectories misdirected toward a phantom source location (0° heading). Most flies were able to resolve an individual source while a smaller proportion of flies walked toward a phantom source location.