A chameleon’s ability to change colors is often cited as a means of camouflage. But according to a new study of chameleon behavior, male chameleons change color as a display of virility rather than as a way to blend into their environment.
After conducting a number of experiments with male chameleons, researchers from Arizona State University found that color shifting was a way for them to keep their territory or a win a female. The study, published in the journal of the Royal Society Biology Letters, notes that the display of power seen in chameleons is similar to the way some animals bare their teeth or drag their hooves.
"This is the first time that anyone has been able to use the visual system of an animal to analyze color change during the behavioral contexts in which such color changes are used," Russell Ligon, a co-author of the study, told Live Science. "It's possible that there is some overall template that the chameleons can recognize and place other individuals on that scale, possibly for them to get a sense for how worthwhile it might be to continue to pursue an interaction or call it off.”
According to HNGN, scientists paired 10 chameleons off in gladiator-like face-offs to see how they reacted. They put them together in 45 different combinations and left them alone for 30 minutes, documenting their movements with hidden cameras.
In cases where the pair did not engage each other – in other words, there was no head-butting, lunging or biting – the chameleon with the duller stripes along his body usually backed away from the chameleon with the brighter stripes. When the chameleons did engage in battle, the one that morphed more quickly and changed to brighter colors regularly won.
"It shows for the first time that the speed of color change can affect contest dynamics — a discovery only possible because of the sophisticated way they quantified color change," Devi Meian Stuart-Fox, a researcher at the University of Melbourne in Australia who was not involved in the study, told Live Science.
The new findings help biologists better understand how animals communicate using various signals.