Chameleon color change as a social signal
To protect themselves, some animals rapidly change color when their environments change, but chameleons change colors in unusual ways when they interact with other chameleons. Arizona State University researchers have discovered that these color changes convey different types of information during important social interactions.
For example, when male chameleons challenge each other for territory or a female, their coloring becomes brighter and much more intense. Males that display brighter stripes when they are aggressive are more likely to approach their opponent, and those that achieve brighter head colors are more likely to win fights. Also, how quickly their heads change color is an important predictor of which chameleon will win a skirmish.
In this video, two male veiled chameleons challenge each other over territory. They turn their bodies laterally to display their colorful stripes, and then intensify their head coloring when approaching each other.