Figure 2. Spectral data on male red coloration and female red sensitivity.

(A) Spectral reflectance for the cheek region of 25 reproductively active males. Plotted is the mean of the reflectance intensities (black line) ± standard deviation of the mean (shaded area). Reflectance was measured relative to a 98% white reference standard. (B) Mean relative sensitivity of daughters at three wavelengths of long-wave light (590, 610 and 630 nm) as measured in optomotor response tests. Error bars indicate standard deviation of the mean.