Bearded dragons (Pogona vitticeps) are lizards native to Australia. They inhabit arid and semi-arid habitats. As well as appearing in zoos around the world, the bearded dragon is also suitable for keeping as a pet, due to his tolerance of handling. The key distinguishing feature of the bearded dragon is the ridge of spikes that adorn his neck. This is the feature from which he takes his name, but these spikes are not all that they seem.
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What is a Spike?
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Reptilian spikes are actually just hardened scales, formed from sections of keratin, the main protein in reptile skin. On bearded dragons, the hardened keratin layers form little spikes, or spines, that protrude from the surface of the skin. Reptilian spikes can be hard, soft, long, short, thick or thin, depending on the way the scales are genetically programmed to develop.
Back and Neck Coverage
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The bearded dragon has spikes on his back and around his neck. The spikes form little ridges. On the neck area, these spike ridges give the appearance of a beard, which is how the bearded dragon got his name. Although the spikes may appear dangerous or potentially painful to touch, they are actually relatively soft. With careful handling, an experienced owner may be permitted by his pet to gently stroke the spikes.
Function of the Spikes
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Bearded dragon spikes are a form of evolutionary mimicry. While they may have an appearance to the contrary, they are relatively harmless. However, the benefit of the spikes is not in the pain or injury they could cause to a predator -- which includes foxes and dingoes -- but in the aversion they would cause a predator. Animals instinctively avoid prey that would either be dangerous to tackle or painful to eat. Those animals that are neither mimic those that are, causing predators to avoid them in the same way they̵7;d avoid more dangerous prey.
Other Methods of Self Defence
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As well as possessing rather fearsome-looking -- though ultimately harmless -- spikes, bearded dragons use camouflage to avoid detection from predators. The sandy color of their scales enables them to blend into the arid landscape, but the scales supplement the color camouflage by creating visual disruption, where the spikes obscure the distinction between the lizard and his background.
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