As many as 180 species of chameleon camouflage themselves in varying habitats across the world. The evolutionary adaptations of this old world lizard is fascinating, a genuine testament to the millions of years Nature has invested on its spectacular design and functioning.
DISTRIBUTION: Found primarily on the mainland of sub-Saharan Africa, roughly 50% of all chameleon species exist in Madagascar. They are also native to southern Europe, north Africa, middle east, Sri Lanka, southern India and select islands of the western Indian Ocean.
As a favourite of the pet market, this gentle reptile has emerged as an invasive species in parts of the United States (Florida, Hawaii, California).
HABITAT: Chameleons are almost always found in warm habitats inhabiting every kind of tropical rainforest, savanna available; also seen in desert and steppe.
BIOLOGY: Best known for their ability to change colour, the chameleon’s locomotion is characterised by swaying gait. They have heavily ornamented faces (especially in males) sporting crests, horns, nasal protrusions or a distinctly shaped head. Their eyes are independently mobile but co-ordinate when focusing on prey. The upper and lower eyelids of a chameleon are fused with a tiny pinhole through which their retinas observe the world in 360 degrees.
Mostly arboreal, a prehensile tail enables them to cling onto wiry tree branches as tong-like limbs carry them forward in a manner so theatrical and distinct unto chameleons. A long, slender highly modified tongue is rolled up when not in use and launched to catch prey.
The very anatomy of the chameleon is adapted for climbing and visual hunting.
MASTER OF DISGUISE: Chameleons the world over are capable of varying combinations of colour as striking as turquoise, yellow or purple. This ability functions as camouflage, social signal and to regulate temperature observed in some cases. The darker colours are reserved for agitation or intimidation; males show multicoloured patterns during courtship. This amazing ability to change colour is employed by some, like the Smith’s dwarf chameleon, in accordance to the quality of vision of different predator species.
How do they do it?
Specialised cells called chromatophores contain colour pigments present in the cytoplasm three layers below a chameleon’s transparent outer skin. The first layer is yellow + red; second is blue or white and the third melanin, a dark pigment that controls how much light is reflected. The colour pigment in each layer rapidly distributes and re-distributes to influence the animal’s colour.
FEEDING: Insectivorous, ballistically project their muscular tongue to capture prey at a distance. A chameleon’s tongue to body ratio is 1 : 1.5 or 2 on an average and temperature heavily influences the amount of food it consumes.
More on the chameleon: