Colors have many functions in the lives of animals. They are used, for example, for sexual and social communication and to protect themselves from predators, either wearing cryptic tones and features that make them go unnoticed or, on the contrary, warning of their supposed danger through striking colors and features. They also play a role in thermoregulation and help filter ultraviolet radiation.
«Animal coloration involves a cascade of physical and biological phenomena that begin when light is transmitted through the habitat, hits the animal’s body and interacts with the pigments and optical nanostructures present in its integument (the layer formed by the skin and its coverings, such as hair, feathers, scales, hooves… ), to then be reflected again in the environment”, explains Gabriela X. Venable, a researcher at the Department of Evolutionary Anthropology at Duke University, in the United States. The observer will capture this light, which, absorbed by his eye pigments, will allow him to perceive color.
Hummingbird feathers account for 84.5% of the colors present in all birds
Venable has been involved in research on the color range of hummingbird feathers. After studying 1,600 samples of plumage from 114 species of hummingbirds (there are 340 described) belonging to 68 genera (of the 102 that exist), have found that these small birds contain 84.5% of the colors present in all birds. “They can display more than 30% of the colors they are capable of perceiving»Venable adds. The secret of such variety? A few lamellar filaments of feathers, called barbules, which house microstructures containing melanin. The position and separation of these microstructures allow the bird to break down light into a wide variety of colors that change hue depending on the position it adopts. A symphony of colors!
This article belongs to the October 2022 issue of the magazine National Geographic.