Top 10 chameleon facts
With high-speed tongues, swivelling eyes and strange life cycles, this family is full of colourful characters
1. Chameleons have unique eyes – they can move independently, giving the animals almost 360-degree vision and the ability to look in two directions at once. They have high-speed focus and, when they spot a potential meal, they can point both eyes in the same direction for binocular vision to give accurate depth perception. This accuracy means they can shoot out their tongue and hit the target, as there’s no second chance at sneaking up on an insect.
2. Most animals stop growing once they’ve reached maturity, but not chameleons. They keep growing throughout their lives, shedding their skin in pieces whenever it becomes too small.
3. Chameleons are found in Africa (including Madagascar), Asia, Spain and Portugal. They can live in a variety of habitats, from savannahs to rainforests, usually preferring to be above ground in vegetation. Some, like leaf chameleons, are well camouflaged for life on the ground among dead leaves.
4. These sneaky lizards creep up on their unsuspecting prey then shoot out a tongue up to twice the length of their body in a fraction of a second. The end of the tongue turns into a sticky suction cup on contact with the unfortunate victim, pulling it back into the open mouth of the chameleon. Strong jaws then take over while the tongue is gathered at the back of the mouth until it’s time to hunt again.
5. Scientists have dated the original chameleons to just after the dinosaurs went extinct, around 65 million years ago, although there’s been some suggestion that they were around 100 million years ago. They’re likely to have evolved in Africa, which would explain why that’s where most species living today are found.
6. Some chameleons can change colour, but it’s not just for camouflage. Instead, these changes are often in response to different temperatures, emotions, and light and humidity levels. Brighter colour in male chameleons indicates that they are more dominant (with less dominant males usually a dull colour) and makes them more attractive. Females can change their skin tone to show that they’re pregnant or to accept the advances of a potential mate.
7. Chameleons don’t have outer ears or ear openings, but this doesn’t mean they can’t hear at all. They can detect sounds with frequencies of 200-600 Hz, much narrower than the average human hearing range of 20-20,000 Hz and worse than the hearing of other reptiles.
8. The smallest chameleon species – Brookesia micra – is also among the smallest of all the world’s vertebrates (animals with backbones). It’s just 2.9 centimetres (1.1 inches) long and was discovered in 2012 on a fittingly tiny island off the coast of Madagascar called Nosy Hara.
9. A chameleon’s skin can change colour in under a minute. These impressive colour changes are achieved by adjusting pigmented cells called iridophores under the top layer of skin. Relaxing or contracting the cells changes the structure of the cell layer and the way that different wavelengths of light reflect off it, altering the colours perceived by other animals.
10. Some species don’t lay eggs, giving birth to live young instead. The young start out inside an egg, but it has no shell and is incubated in the mother instead of a nest.
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