These attractive, intriguing, largely arboreal lizards are such unusual animals that for a time they were not placed in the taxonomic sub order sauria (lizards) but in their own sub order, Rhiptoglossa. In the 19th century, two genera were recognized chamaeleo and brookisea, the former mostly large, colourful, prehensile tailed chameleons.
Chameleons have a number of un-lizard-like characteristics .the tail cannot be shed and re-grown, and is prehensile in all species of chameleon. Their eyes are set in small turrets, move independently; their vision is sharp and can be binocular; they have no external ears and consequently very poor hearing. Their feet are uniquely adapted for climbing ,with opposed bundled toes with sharp claws; consequently chameleons are arboreal the bigger species ascending to the bigger heights in trees, although the small species prefer shrubs and bushes and the pygmy chameleons often forage on the ground, although they climb into low vegetation to sleep. Chameleons have a telescopic tongue that can be shot at prey, to a distance greater than their bodies. They can change colour and intensity rapidly; some species exhibits a wide range of colours. Their bodies are curiously laterally compressed, without an obvious neck. The sex organs of the male are located in sheath at the base of the tail, and thus an adult non-horned chameleon can often be sexed by examining the tail base, which is broader in males. Males of some species have tarsal spurs, small scaly projections on the heel. The ability of change colour has made chameleons famous. The colour change is connected with their emotional /hormonal state, but usually matches the back ground. The colour change are also responsive to light, shade, and temperature .body shape, the way they move and base coloration all contributes to camouflage; patterns and intensity colour change are hormonally controlled. chameleons cannot move fast and their only active defences are hissing, biting, and jumping from perch .however ,if sexually aroused or facing a rival (some territorial),vivid, stunning colour patterns may appear ,and angry or harassed chameleons will darken ,showing patterns of dark bars, spots or blotches; some become black with rage. In cold area, they will turn black in the early morning ,in order to absorb heat and light efficiently from sun; at the same time they carefully align themselves perpendicular to the light and flatten the body to increase surface area.
A number of East African species have one, two or three annular or blade –like horns and rival males will fight with these, as well as by biting or clawing. The low altitude lay eggs, but most high altitude species ,especially the Tanzanian hill species and the smaller, stripped East African species of the ‘’trioceros’’ group which includes Jackson chameleon (chameleo jacksoni) and the side striped chameleon (chameleon bitaeniatus) give live birth. Chameleons eat insects and other arthropods (millipedes and spiders) and are thus farmers friendly. Chameleons have many enemies, including various species of birds (shrikes, starlings), small tree climbing carnivores, tree snakes (boom slang, twig snakes).
There are more than 130 known species of chameleon ,60 or more occur in Madagascar ,the rest mostly in sub-Saharan Africa, although a few species are found in Mediterranean sea and on Arabian peninsula ,one species occurs in India and sri Lanka, other on smaller off-shore islands. Tanzania, with more than 25 species, has the greatest chameleon diversity in Africa. In much sub Saharan Africa, chameleons are greatly feared, superstition connected with their secretive life, camouflage, odd appearance and jerky movements. Although some people believe they are venomous, most stories associate chameleons with bad luck, evil eye or having brought death to mankind by some sort of negligence. As a result of such legends, many people fear chameleons and wont tolerate them near homes. Chameleon bodies and body parts may also be used in witch craft.