Fig. 2.

Reflectance spectra for Anisognathus plumage patches across the passerine range of spectral sensitivity. Shown are mean (replicates × patch × subspecies) reflectance spectra for back (a), shoulder (b), and breast (c) plumages of A. notabilis, A. flavinuchus cyanopterus (black-backed subspecies), and A. flavinuchus victorini (olive-backed subspecies). Shaded region indicates UV waveband (320–400 nm). See ref. 11 for additional details on recording equipment and methods. For back plumage (a), note variation in reflectance amplitude and shape between subspecies of A. flavinuchus, which parallels the distinction between sympatric A. notabilis and A. flavinuchus cyanopterus.