Figure 2.

Relative densities and absorbance spectra of Empidonax oil droplets. (A) Ratios of oil droplet density in the retina of typical passerines³ (white bars), the entire retina of Empidonax flycatchers (medium gray bars), areas of Empidonax retinae where MMOD-complex photoreceptors are absent (light gray bars), and areas of Empidonax retinae where MMOD-complex photoreceptors are present (dark gray bars). Values on the Y-axis are the ratios of the different oil droplet types on the X-axis to T-type oil droplets. Statistically significant differences are denoted by an asterisk. (B) Absorbance spectra of Empidonax oil droplets. The orange line corresponds to the MMOD-complex. The gray lines correspond to the traditional oil droplets.