COMPLEX COLORING

We delight in the glittering plumage of hummingbirds, those iridescent colors produced by the nanostructure of the feathers’ flattened barbules with tiny air pockets. But, frustratingly, the colors we perceive depend on the triangulation of the bird, light source, the observer. The apparent color of a hummer’s gorget can change with changing angles of light, often appearing all black. Rose or violet colors can look iridescent green or gold at some angles. Furthermore, individual hummingbirds may vary slightly in gorget feather nanostructure, resulting in slightly different iridescent shades – such as an “orange-throated” Ruby-throated Hummingbird. These complex colors aren’t just there to delight and befuddle us humans. Hummingbirds, like other birds, have a fourth color cone in the retina, sensitive to ultraviolet wavelengths. They can distinguish colors – particularly non-spectral…