Fig. 3. Towhees resolve azimuth well in the field and perform nearly as well in the laboratory. Thick gray line denotes cumulative distribution of flight error observed in field experiments (Fig. 1A; N=298). Thin gray line denotes cumulative distribution of flight error after subtracting error that can be attributed to perch distribution in Florida scrub habitat (see text). Closed symbols denote performance observed in our auditory two-alternative forced-choice (2AFC) task as a function of speaker separation angle (noise 2–5 kHz; N>98; Fig. 1B). Data for each subject tested in this task are plotted separately. Open symbols denote performance observed as a function of speaker separation angle in previous 2AFC tasks conducted with other small birds (Klump et al., 1986; Park and Dooling, 1991). Asterisk denotes performance estimated for the barn owl, Tyto alba, using several methods deemed comparable with a 2AFC task (Bala and Takahashi, 2000).