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.

SUCCESSFUL HAWAIIAN CHAMELEONS

There are no native American chameleons, although there are many pet chameleons. Normally, the survival rate of imported chameleons is very low; they do not often live long in captivity. In 1972, however, thirty-six Jackson's chameleons were sent from Kenya, in Africa, to a pet store owner in Hawaii. Because the chameleons were so stressed from travel, the store owner released them. Some of these chameleons survived and multiplied on the island of Oahu. Jackson's chameleons are quite unusual in that they are the only chameleons in the United States that live and breed in the wild. There are now reports of wild populations in California, Texas, and parts of Florida.

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.

GEOGRAPHIC RANGE

Chameleons are found mainly in Madagascar and Africa, and a few species live in southern Europe, Asia, the Seychelles and the Comoros. No chameleons are native to the Americas, which means that all of them were brought into the Americas. One species is now found there in the wild.

HABITAT

Chameleons live in a variety of habitats, such as dry deserts; tropical, rainy woodlands of evergreens; forests with trees that lose their leaves in winter; thorn forests; grasslands; scrublands, or land with low bushes and trees; and cloud forests, or wet, tropical, mountain forests. They can be found from sea level up to mountainous areas as high as 15,000 feet (4,572 meters).

DIET

Chameleons eat a variety of flying and crawling insects, including butterflies; insect larvae (LAR-vee), or young; and snails. The larger chameleons eat birds, smaller chameleons, lizards, and sometimes snakes. Chameleons also eat plant matter, including leaves, flowers, and fruits. Some chameleons stay within small areas for their food supply, but others travel long distances seeking food. All chameleons need drinking water, which they get from dew or rain.

BEHAVIOR AND REPRODUCTION

Chameleons are cold-blooded animals, meaning that their body temperature varies with the weather. After resting during the night, they warm up in the daytime by basking, or resting, in the sun. If they get too warm, they lower their body temperature by resting in the shade. All their activities take place during daylight hours.

Most chameleons prefer to live alone. Males are very territorial, or protective of their living areas. Males and females tolerate each other only briefly, during the mating season. When males with bony head horns fight over territory, one may lower its head and attempt to ram the other with its horns. Usually no harm is done, unless an eye or lung is damaged.

In the mating season, males try to attract females by bobbing their heads, inflating their throats, puffing up their bodies, and displaying their brightest colors. A female may accept or reject the courting male. If she rejects him, she might run away or she might face the male and hiss at him with an open mouth. She might even attack and bite him. These bites can kill.

Most chameleon species lay eggs. Eggs are placed in tunnels or pits in the ground or under rocks or leaves. This keeps them cool and moist. After laying their eggs, females cover the area with dirt to hide it from predators. Depending on the species, young chameleons hatch one to eighteen months later. They are independent at birth and must find their own food and shelter. A few chameleon species give birth to live young, rather than lay eggs. These species often live in areas where the weather is very cold in winter and where eggs placed directly on the ground might not hatch because of the cold.

CHAMELEONS AND PEOPLE

Chameleons do not normally interact with people. Wild chameleons are sometimes caught and sold to tourists. Chameleons are also taken from their habitats in the illegal pet trade, and many die from stress or improper care. Habitat destruction, forest fires, and air and water pollution, or poison, waste, or other material that makes the environment dirty and harmful to health, are major problems.

CONSERVATION STATUS

The World Conservation Union (IUCN) lists four chameleon species as Vulnerable, meaning that they face a high risk of extinction in the wild. One is Endangered, meaning that it faces a very high risk of extinction in the near future, and one is Critically Endangered, meaning that it faces an extremely high risk of extinction.

JACKSON'S CHAMELEON (Chamaeleo jacksonii): SPECIES ACCOUNTS

Physical characteristics: The body color of Jackson's chameleon can be shades of green or brown, with dark red, yellow, or blue on the head, sides, or tail. Males have three large, pointed, hornlike protrusions on their heads, which are used in fights with other males. Females may or may not have these "horns." Adults grow to 14 inches (35.6 centimeters) in length.

Geographic range: Jackson's chameleon is found mainly in the lower mountain ranges of eastern Africa. There is a wild population in Hawaii.

Habitat: Jackson's chameleon lives in areas with warm days and cool nights, including moist forests, crop plantations, and dense bushes.

Diet: Jackson's chameleons feed on a wide variety of insects.

Behavior and reproduction: Jackson's chameleons live in trees. They are usually calm creatures, but during courtship the male is very territorial and will fight to defend its living area or the female with whom it wants to mate. These fights are shoving contests using the horns. Males court females with their most brilliant colors and with head bobbing. Females give birth to three to fifty live young. Young are ready to reproduce at about six to ten months of age. In the wild these chameleons may live two to four years.

Jackson's chameleons and people: Jackson's chameleons do not interact with people in the wild. They are captured for the illegal and legal pet trade, and they typically do not survive well in captivity. Their living areas are suffering destruction.

Conservation status: Jackson's chameleons are not threatened, but they may become threatened unless their capture for the pet trade is closely controlled. ∎

ARMORED CHAMELEON (Brookesia perarmata): SPECIES ACCOUNTS

Physical characteristics: The armored chameleon is reddish brown, brown, and tan. It has a row of pointed scales projecting from its spine, decreasing in size from the neck to the tail tip. The rest of the body has many thorny scales, giving it an armored appearance. Adults are 6 inches (15.2 centimeters) long.

Geographic range: Armored chameleons are found only in the Tsingy de Bemaraha Nature Reserve in Madagascar.

Habitat: Armored chameleons inhabit bushes, shrubs, and leaf litter in or near dense, dry, deciduous (di-SID-joo-wus) forest, or forests with trees that lose their leaves in cold weather.

Diet: The armored chameleon feeds on insects and insect larvae.

Behavior and reproduction: The armored chameleon is calm and secretive. It spends most of its life on the ground and does not move about much. Little is known about its breeding habits.

Armored chameleons and people: Armored chameleons are rarely seen; they hide and do not interact with people in the wild. They are collected for the illegal pet trade, but few survive once they are captured.

Conservation status: As a result of habitat destruction and collection for the pet trade, the IUCN has listed the armored chameleon as Vulnerable, meaning that it faces a high risk of extinction in the wild. ∎

COMMON CHAMELEON (Chamaeleo chamaeleon): SPECIES ACCOUNTS

Physical characteristics: The colors of the common chameleon vary widely; they include green, yellow, gray, and brown, with many stripes and spots.

Geographic range: Common chameleons inhabit Europe, the Middle East, and northern Africa.

Habitat: Common chameleons are found in many different areas, among them, semidesert scrubland, coastal scrubland, crop plantations, and forested areas as high as 8,500 feet (2,591 meters).

Diet: Common chameleons eat insects, young birds, and small reptiles.

Behavior and reproduction: Common chameleons living in areas with very cold winters will lie dormant, slowing down or entirely stopping most of their activities until the weather warms up. At the onset of warm weather, mating begins. Females carry their young for two months and then produce about sixty eggs. The young hatch in six to eleven months.

Common chameleons and people: Common chameleons do not interact with people in the wild. They are sometimes killed crossing roadways. They are also captured for the illegal pet trade, but few survive. Habitat destruction is another threat.

Conservation status: The IUCN lists the common chameleon as Vulnerable. Only in Greece are they strictly protected. ∎

FOR MORE INFORMATION

Books:

Bartlett, Richard D., and Patricia Bartlett. Jackson's and Veiled Chameleons. Hauppauge, NY: Barron's Educational Series, 2001.

Darling, Kathy, and Tara Darling. Chameleons: On Location. New York: HarperCollins, 1997.

Mara, W. P. Chameleons: Exotic Lizards. Mankato, MN: Capstone Press, 1996.

Miller, Jake. The Chameleon: Lizard Library. New York: PowerKids Press, 2003.

Schmidt, W., K. Tamm, and E. Wallikewitz. Chameleons: Basic Domestic Reptile and Amphibian Library. Broomall, PA: Chelsea House Publishers, 1998.

Stefoff, Rebecca. Chameleon. New York: Benchmark Books, 1996.

Uchiyama, Ryu. Reptiles and Amphibians. San Francisco: Chronicle Books, 1999.

Periodicals:

Cooper, Sharon Katz. "Chameleons and Other Quick-Change Artists." National Geographic Explorer (October 2002): 4–7.

"Chameleons' Emotional Signals." National Geographic (August 1993): Earth Almanac.

"Panther Chameleons." Ranger Rick (February 1998): 5–9.

Risley, T. "Chameleon Profile: Brookesia and Rampholeon. Chameleon Information Network 31 (Spring 1999): 21–23.

Risley, T. "The Fate of Wild-Caught Chameleons Exported for the Pet Trade." Chameleon Information Network 42 (Winter 2001): 15–18.

Web sites:

Fry, Michael. "Introduction." Chameleon Information Network.http://www.animalarkshelter.org/cin/ (accessed on July 29, 2004).

Heying, Heather. "Family Chamaeleonidae." Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Chamaeleonidae.html (accessed on July 28, 2004).

Mayell, Hillary. "Evolutionary Oddities: Duck Sex Organs, Lizard Tongue." National Geographic News.http://news.nationalgeographic.com/news/2001/10/1023_corkscrewduck.html (accessed on July 29, 2004).

Raxworthy, Christopher J. "A Truly Bizarre Lizard." Madagascar—A World Apart. http://www.pbs.org/edens/madagascar/creature3.htm (accessed on July 29, 2004).

"Veiled Chameleon." Reptiles & Amphibians: Smithsonian National Zoological Park. http://national http://nationalzoo.si.edu/Animals/ReptilesAmphibians/Facts/FactSheets/Veiledchameleon.cfm (accessed on July 29, 2004).