Chameleons: Chamaeleonidae - Physical Characteristics

Chameleons (kuh-MEEL-yuns) are best known for their ability to change colors easily. Once, color change was thought to serve as camouflage (KA-mah-flahzh), or a sort of disguise, allowing the chameleon to match or blend in to its surroundings. Scientists now believe that colors change in response to differences in temperature, light, and the chameleon's mood. Colors may change in both males and females or only in males, depending on the species, or type, of chameleon. Some species can change color only into shades of brown. Others have a wider color range, turning from pink to blue or green to red. Varieties of color may be displayed on different body parts, such as the throat, head, or legs. When the chameleon is excited, stripes or patterns may appear. Sleeping or ill chameleons tend to be pale.

Chameleons range in length from 1 inch (2.5 centimeters) to 26.8 inches (68 centimeters). Males may be larger or smaller than females. A chameleon's body is flexible (FLEK-suh-buhl), meaning that it can bend easily. It can be rather flat from side to side and shaped somewhat like a leaf. This allows it to blend better with leafy surroundings. A chameleon can also make its body look longer, to seem more a part of a twig. If it is threatened by a predator (PREH-duh-ter), or an animal that hunts it for food, the chameleon can inflate, or puff up, its lungs and make its rib cage expand, to appear larger.

Chameleons have long, slim legs, with four feet. There are five toes on each foot. The toes are fused, or joined, in bundles of two and three toes to form a pincer (PIN-suhr), a kind of claw for grabbing and holding. Sharp claws on each toe aid in climbing. The tail is formed in a way to help the chameleon hold on to twigs and branches.

These animals have large eyes that protrude, or stick out. Each eye can move independently of the other, so the chameleon can look in two directions at once. For this reason, chameleons can look forward, sidewise, or backward without moving their heads, and they can follow moving objects without changing their body position. If they see an insect, they will focus both eyes on it to see how far away it is.

A chameleon's tongue can extend the length of its entire body, or even longer. The sticky tongue can flick out to full length within one-sixteenth of a second, fast enough to catch a fly in midair. The tongue tip is like a wet suction cup that attaches to its prey, or an animal that it hunts for food. A chameleon can capture and pull in prey weighing up to about half of its own body weight. Then the chameleon relaxes its tongue, with prey attached, and draws it slowly back into its mouth. Chameleons also use their long tongues to lap up water from leaves and other surfaces.

A chameleon's head can be covered with many bumps and bulges and other body structures that stick out. Scales on its back can resemble small or large crests, or ridges. Some crests are barely noticeable, but others are quite large. Body scales also can be found on the throat and belly. On the sides of the head there may be movable skin flaps. Bumps and growths of differing sizes may be seen on the snout, or nose area. Depending on the species, chameleons also may have one to six bony "horns," of varying sizes and shapes, on their heads. Although chameleons do not have vocal cords, or body parts used to produce sound, some species can make a hissing or squeaking noise by forcing air from their lungs. Others can vibrate (VIE-brayt), moving back and forth rapidly to create sound.