Chameleon turquoise, and purple. Chameleon skin has a superficial layer which contains pigments, and under the layer are cells with guanine crystals. Chameleons change colour by changing the space between the guanine crystals, which changes the wavelength of light reflected off the crystals which changes the colour of the skin. Colour change in chameleons has functions in camouflage, but most commonly in social signaling and in reactions to temperature and other conditions. The relative importance of these functions varies with the circumstances, as well as the species. Colour change signals a chameleon's physiological condition and intentions to other chameleons. Chameleons tend
Camouflage giraffes move about to gain the best view of an approaching predator, relying on their size and ability to defend themselves, even from lions, rather than on camouflage. A different explanation is implied by young giraffes being far more vulnerable to predation than adults: more than half of all giraffe calves die within a year, and giraffe mothers hide their calves, which spend much of the time lying down in cover while their mothers are away feeding. Since the presence of a mother nearby does not affect survival, it is argued that young giraffes must be very well camouflaged; this