Can Chameleons really change colour to match any background

A. No, the range they can produce is limited and therefore cannot correspond exactly to any background. Each chameleon has a basic colour, which broadly matches its habitat. Changes in colour are subtle, rather than dramatic, and are actually triggered by changes in light and shadows, which affect the colours of their surroundings, or are a response to their moods and willingness to mate.

Q. What colours can chameleons change to

A. Chameleons turn many shades, including brown, green, blue, yellow, brick red, black, and white. Their colours can be solid or patterned. A chameleon partially shaded from sunlight by a leaf will actually display a sort of reverse shadow, a light patch on its sun-darkened skin.

Q. How quickly can they change colour

A. In less than a minute. Many fish can also change colour but none as quickly as the chameleon.

Q. How do they change colour

A. There are two layers of cells, called chromatophores, under a chameleon's outer transparent skin, which contain yellow and red pigments. Beneath the chromatophores are layers that reflect white and blue light. Beneath these layers lies melanin, the chemical that causes humans to tan in the sun.

Chameleons change colour when excitement, anger or bright light triggers expansion in the colour cells which causes a difference in the reflected colour mix. This mix changes again as the colour cells shrink back. The green of a calm chameleon is created when yellow pigment partially blocks the blue-reflecting layer underneath. Conversely, an angry chameleon turns yellow because so much yellow pigment is transmitted that it completely blocks out the blue underneath.

Q. How many species of chameleon are there

A. About 128 distinct species. Each species has its own range of colour, with green and brown being the dominant colours.

Q. How long do chameleons live

A. In the wild, it isn’t known, but is thought to average about two years, with some reaching up to six years of age. In captivity, they have been known to live up to twelve years.

Q. How big can they grow

A. The smallest species is just one inch long whereas the biggest can grow to two feet.

Q. Is changing colour a chameleon's only trick

A. No, they're unique among reptiles in that they can move each eye independently of the other, enabling them to view two different scenes at the same time, very useful for hunting or looking out for predators.

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by Lisa Cardy