Laurie Noreau – The Rumor Detector – Agence Science-Presse
From red to green via yellow and purple: certain videos would lead you to believe that if you plop a chameleon on any color surface, it will quickly tint its skin to match the surface. But are chameleons really nature’s camouflage champions? The Rumor Detector finds out.
First thing is that most chameleons already have a skin color that lets them blend in with their natural surroundings. That’s why it’s frequently tough to tell a chameleon from branches or leaves. Since it is basically defenseless, it camouflages itself to remain invisible to predators and stay alive in the jungle or in the desert.
Some species of chameleon can make small adjustments to their tint according to the surrounding light. For example, in a darker environment it can tint its skin darker.
Generally only the males have this ability. Females and children are one constant color, usually dull. In certain species, females will take on vivid colors during their reproductive cycle, but they have a limited range of tints. We’re a long way from the spectacular changes of color that let the animal change from one bright color to another in a finger snap.
The most impressive color changes occur when one male is in competition with another. Whether it’s to defend his territory or court a female, the chameleon will take on a very bright color, like yellow. If he loses the combat, he will adopt a much darker color as a sign of submission. Nonetheless, you’ll have to wait a whole minute and a half before that color change comes through.
How it Works
In 2015, scientists succeeded in piercing the mystery of a chameleon’s camouflage. It’s all thanks to cells called iridophores. These cells contain crystals which reflect light. When relaxed, these cells appear to be blue, green and red on a chameleon’s body. But when the reptile is excited the distance between the crystals increases. This rearrangement reflects different wavelengths of light, and therefore, different colors.
So a chameleon can make a colorful display of oranges and yellows to intimidate another male, or to impress a female.
Other researchers have noted that chameleons can use its color changing abilities to regulate its own body temperature. Like other reptiles it is cold blooded and it stays warm by being in the sun. If it needs to cool down, many species will adopt a lighter color to reflect light. When the mercury falls, many species will take on a darker color, to better absorb light and heat.
Verdict
Yes, the chameleon does modify the color of its skin in its natural habitat. It does this to camouflage itself, to defend itself against other males and to regulate its body temperature, as well as to attract a mate. But most species don’t perform spectacular metamorphoses nor can any of them change their tint to be the same color as a surface it is plopped on.
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