An O'Shaughnessy's Chameleon seen on the roadside at Ranomafana

The Nose Horned Chameleon is common in the rainforests of eastern Madagascar. They're quite easy to identify thanks to a protrusion giving the tiny chameleon a 'nose'. It is typically found in low vegetation, usually up to 3m off the ground. They can reach sizes of roughly 10cm. They were fascinating to watch as they moved slowly through vegetation. How they managed to hang on in the strong breeze we often had on night walks I'm not sure as they seemed so delicate. Nose Horned Chameleons were the most common species we saw in Madagascar, although only in the eastern rainforests of Ranomafana and Andasibe.

O'Shaughnessy's Chameleon is classed as vulnerable by the IUCN Red List of Threatened Species. As with all species in Madagascar, it is threatened by the loss of habitat due to slash-and-burn agriculture and logging for construction. The chameleon gets its name from the British poet and herpetologist Arthur O'Shaughnessy who discovered it. It's range is larger than that of the Nose Horned Chameleon as it is found not only in the rainforests of eastern Madagascar but also in the central highlands as well. They can reach lengths of up to 40cm including their tail.

Chameleons are very popular with people often because of the myth that they change colour to match their surroundings. This isn't true, they change colour depending on their mood. An angry or upset chameleon usually changes to mostly black in colour. They are able to change their colour thanks to a layer of skin cells that contain floating nanocrystals. These tiny crystals are roughly evenly spaced throughout the cell. This spacing determines the wavelength of light that the cells reflect. Contrary to what most people think, when a male chameleon comes across another male competitor or a potentially receptive female, it shifts the background colour of its skin from green to yellow, its blue patterning turns white and red becomes brighter. How they managed to evolve this trait isn't quite clear but nonetheless it is an amazing ability.

Another feature of chameleons which I love is their prehensile tail. The term prehensile is taken from the Latin 'prehendere' which means 'able to grasp'. Chameleons use their prehensile tail as a 5th limb to grasp branches as they climb through the trees.