Color Change for Survival

Changeable Charlie Chameleons have a reason for their unique color shows:

Chameleons rapidly change color by actively tuning photonic crystal-like structures in their skin, finds new research.

The study, published in the journal Nature Communications, reveals that -- unlike other creatures that rely on the accumulation or dispersion of pigments -- chameleon color shifts happen due to structural changes that affect how their skin reflects light.

Usually chameleons like to blend in with their surroundings, but threats or the possibility of mating will cause males to put on their bolder color display.

"Only mature males can change color, and they do so when they see another mature male or a potentially receptive female," senior author Michel Milinkovitch told Discovery News.

"The very visible colors impress the other male (to chase him away) or the female (to attract her)," Milinkovitch, a professor in the Department of Genetics & Evolution at the University of Geneva, said.