Bearded Dragon - AS

Scientific Name: Pogona vitticeps

The central bearded dragon is stout and thorny in appearance and can be up to 60cm long. Its body is slightly flattened and an assortment of specialised scales covers the lizard. They have spiny projections around the skin flap (the guttural pouch). Hanging from the neck and throat it can be inflated and fanned outward into a “beard” and turned to black when the dragon is threatened, giving it its name. These dragons are predominantly grey with some variations toward orange, fawn, brown, and black. They are frequently yellow around the eyes and at the side of the head. Colouring is largely dependant on locality and temperature. These lizards are found in eastern areas of the Northern Territories and in the eastern half of South Australia. The species’ habitats include temperate to tropical arid to semi-arid woodland, shrubland and hummock grassland.

Adaptations
Central bearded dragons are semi-arboreal - they spend as much time in the trees as on the ground. They are excellent climbers and runners as they have stout legs and long, clawed digits, and with these, bearded dragons can ascend to basking sites. On the ground their colouring allows them to blend into their surroundings. These young dragons constantly shed their skin in shreds and patches.

During the cooler months of spring and summer, they can be active most of the day. As temperatures rise, they bask during the early morning or late afternoon but during the heat of the day they are inactive and take cover in crevasses and underground. In the evening Bearded dragons can be found on sun-warmed roadways; rocky niches and empty dens that keep them warm at night. During extended periods of cool temperatures, they will occupy abandoned burrows or crevasses. Tail fat is a source of food during such times. They also thermoregulate by using their limited ability to change colour: brighter for cooling off, darker for warming up, as a darker colour absorbs more infra-red radiation. Their long legs let them lift their bellies off the hot desert surface. While they move more slowly, cooler air flowing around their bodies lets them run for longer. Bearded dragons also open their mouths when it is too hot so water in saliva evaporates cooling the body; this is known as 'gaping'. Since water can be pretty scarce in its environment, the bearded dragon rarely drinks from water sources, instead it gets all its water needs from the prey it eats. They are extremely efficient at using the water from these organisms. Bearded dragons also stretch their rib cage to increase surface area by three times and so increase absorption of light.