Chameleon, a tree-dwelling lizard having the ability to change color and to move each eye independently. The color change is involuntary, contrary to common belief, and is brought about by light, temperature, and nervous stimulation such as anger or fear. It is not related to the color of the substance on which the chameleon happens to be.
Under ordinary conditions, the rough skin of the chameleon is a dull brownish-green. Under stresses of fear or anger, the color changes to a vivid green; it turns brown or yellowish-gray in response to hunger, low temperatures, and strong sunlight. The males of some species may display a brilliant red dewlap (a loose fold of skin under the throat) during courtship or in combat.
A chameleon is able to change its skin color quickly. This lizard may be green, yellow, or white one minute, and brown or black the next. Chameleons also may become spotted. The chameleon’s color is controlled by body chemicals called hormones (HAWR mohnz).
Many people believe chameleons change color to blend with their surroundings in order to hide from predators. This, however, is not true. Chameleons actually change their color depending on the air temperature or the amount of light, though most often the animal changes color because of its mood.
The skin of a chameleon is see-through, or transparent. The chameleon has cells underneath this skin that contain pigment (a natural substance that controls the color of tissues in animals). By increasing the size of certain pigment cells and decreasing the size of other pigment cells, the chameleon changes color. For instance, if a chameleon decreases the size of its black-pigment cells and increases the size of its yellow, its skin changes from black to yellow.
About 90 species of chameleon are known. They are native to Africa, Spain, Madagascar, India, and Sri Lanka.
Unlike most lizards, the chameleon is not slender and swift. Including the tail the length of some pygmy chameleons is four inches (10 cm). The largest species, found in East Africa, is almost two feet (60 cm) long. The head has a hoodlike rear projection. Its feet are adapted to grasping, each foot having five toes arranged in pincer-like groups of two and three. The tail can be wrapped around twigs. The large eyes can be rotated, either independently of each other or in unison. The eyelids form a circular fold with a small central opening. The sticky, blunt-tipped tongue of the chameleon is almost as long as its body. It darts rapidly from the mouth at insects, which make up the chameleon's diet.
Certain anoles—tropical American lizards of the genus Anolis—have the ability to change color from dark brown to green and are mistakenly called chameleons. The “chameleons” sold in pet shops and at carnivals belong to this genus. One species is native to the states along the Gulf of Mexico and to parts of the West Indies. Another species is found in the West Indies and the southern tip of Florida. There are more than 100 related species in the West Indies and Central and South America.
A male Jackson’s chameleon has three ridged horns on its head. One horn is on the lizard’s snout and the other two are above its eyes. The horns make this lizard look something like the dinosaur Triceratops (try SEHR uh tops), whose name means three-horned face.
Male Jackson’s chameleons use their horns when they fight other males over territory or possible mates. When they fight, the males use their horns the way a medieval knight used a lance while jousting. These chameleons may also use their horns to help attract mates. And scientists think the horns help Jackson’s chameleons recognize others of their own species.
Female Jackson’s chameleons do not have fully developed horns. They have only three small lumps or a single spike on their head.
Chameleons belong to the family Chamaeleontidae. The common chameleon is Chamaeleon chamaeleon. Pygmy chameleons are of the genus Brookesia. The large East African chameleon is C. melleri.
Anoles belong to the family Iguanidae. The anole of the Gulf states is Anolis carolinensis. That of southern Florida is A. sagrei.