Chameleons use some “colorful” language to communicate with one another, but not the kind loaded with four-letter words. Long-known to be a defensive tactics, the chameleon’s camouflage changes get a little… weirder. ASU researchers have discovered that these strange color changes don’t happen randomly. Instead, they’re used to convey different types of information during social interactions.

As an example, when males challenge one another for something desirable (like a female or new territory), their color stripes become much brighter and more intense. The brighter the color, the more likely the male is to both engage in and win an altercation. The researchers also found that how rapidly the colors change are also a reliable indicator of the likelihood of victory.

“We found that the stripes, which are most apparent when chameleons display their bodies laterally to their opponents, predict the likelihood that a chameleon will follow up with an actual approach,” said Russell Ligon, a doctoral candidate in ASU’s School of Life Sciences. “In addition, head coloration — specifically brightness and speed of color change — predicted which was lizard was going to win.”

Ligon, along with associate professor Kevin McGraw, used modeling tools and algorithms to study 28 different pigment patches on veiled chameleons (Chameleon calyptratus). Distance, maximum brightness, and speed of change were among the variables they studied.

All chameleons tend to default to brown or green shades in order to blend in with foliage, but each specimen has its own, unique set of markings. When the gauntlet gets thrown, yellows, oranges and even turquoises can become visible. When the combatants are ready to face one another, the important color signals on the head area become prominent.

“By using bright color signals and drastically changing their physical appearance, the chameleons’ bodies become almost like a billboard — the winner of a fight is often decided before they actually make physical contact,” Ligon said. “The winner is the one that causes its opponent to retreat. While sometimes they do engage in physical combat, these contests are very short — five to 15 seconds. More often than not, their color displays end the contest before they even get started.”

It’s like gang warfare, only with flamboyant lizards.