Social Chameleon
Short Horned Chameleon; Calumma brevicornis © California Academy of Sciences
DB: This is Earth and Sky, with a question from a listener. She writes, “How do chameleons sense the colors of their surroundings in order to change their own colors?”
JB: Chameleons actually don’t change their colors to match their surroundings. They change colors in order to communicate. They flash an array of patterns and shades mainly to show their moods and intentions – much as we humans use our facial expressions.
DB: But we mostly have control only over whether we look angry or happy. Chameleons wear their hearts on their sleeves. A chameleon’s color at any given time is based on complex interactions between its hormones and pigment cells. This hormonal reaction can be triggered by a number of factors, such as sickness – or the presence of a competitor. Male chameleons, for example, display their color signals either as war paint to scare off a rival, or as a bouquet of flowers, to court a mate. Females, on the other hand, have their own distinctive palette to show whether or not they’re available.
JB: When a chameleon changes color, it’s likely to become more visible, not less. Its transformation isn’t so much a camouflage as a coded message. You too can send us a message – or ask a science question – at our website, earthsky.org. Thanks today to the National Fish and Wildlife Foundation and to the National Park Service – supporting the conservation of native fish, wildlife, plants and their habitats. We’re Block and Byrd for Earth and Sky.
The following person was interviewed for today’s program. Our thanks to:
Dr. Carl Gans
Department of Biology
University of Michigan
If you enjoyed this show, the following book may be of further interest to you:
Le Berre, Francois. The New Chameleon Handbook. Hauppage: Barron’s, 1995.
Author’s notes:
Chameleons do have some tricks to hide within their environments, but they don’t involve color. Their bodies are just about all lung, so they can squeeze themselves thin and hide behind small sticks. They wait for wind before moving, and then shake as they walk, perhaps to imitate a rustling leaf.
Additional Teacher Resources
NASA, Earth Observatory, Features: Uncovering Chameleons
This article explores the incredible diversity of chameleons in the differing topographic and climactic regions of Madagascar. Madagascar?separated from the southeast coast of Africa more than 80 million years ago?through its isolation and wide range of ecosystems, has fostered the evolution of an extraordinary variety of species of chameleon.
Public Broadcasting Service, The Living Edens, Madagascar?A World Apart: Creature Features: A Truly Bizarre Lizard
Chameleons are an extremely unique species in their own right. Known for their ability to change color, they can be seen wearing a variety of colors, including brown, green, blue, yellow, red, black or white. This informative article explains how communication is an important reason behind these color changes, with color chameleons can communicate with others, expressing attitudes such aggressiveness, passivity or their willingness to mate.
MONGABAY.COM: Chameleon Photos
This site contains a wide variety of photographic images of several species of chameleons from around the globe.
