Coloration strategies in peacock feathers

TLDR

Peacock feather coloration is achieved by adjusting the lattice constant and number of periods in a photonic‑crystal structure. The study investigates the mechanism of color production in peacock feathers. The cortex’s 2D photonic‑crystal structure creates a partial bandgap that reflects light, and altering its lattice constant or reducing periods generates diverse and mixed colors.

Abstract

We report the mechanism of color production in peacock feathers. We find that the cortex in differently colored barbules, which contains a 2D photonic-crystal structure, is responsible for coloration. Simulations reveal that the photonic-crystal structure possesses a partial photonic bandgap along the direction normal to the cortex surface, for frequencies within which light is strongly reflected. Coloration strategies in peacock feathers are very ingenious and simple: controlling the lattice constant and the number of periods in the photonic-crystal structure. Varying the lattice constant produces diversified colors. The reduction of the number of periods brings additional colors, causing mixed coloration.