Central Bearded Dragons usually grow to be about two feet in length, with the tail accounting for over half of the total body length. Males can be distinguished from females, as males have a wider cloacal opening, the base of the tail is wider, the head is usually larger with a larger beard (often black) and possess hemipenes. Males also have more pronounced femoral pores than females (these can be seen as waxy bumps on the underside of the back legs). Bearded dragons vary widely in colour, including brown, grey, reddish-brown, red, yellow, white, orange, but there is yet to be a green bearded dragon. They are capable of undergoing moderate changes in the shade of their colour to help regulate temperature. The specialized scales along both sides of the throat, neck, and head form many narrow spines which run down the side of the body to the tail. When feeling threatened, a bearded dragon will flatten its body against the ground, puff out its spiny throat, and open its jaws to make itself appear larger. The bearded dragon is so named because of the pouch-like projection (also called the guttural pouch) on the underside of the neck and chin area which typically turns darker than the rest of the body. It also boasts spiny projections. Both of these characteristics appear similar to a human's beard. Males typically have a darker "beard" than females, and during mating season and courtship it will typically darken to near-black. The bearded dragon, like most agamid lizards, has strong legs which enable it to lift its body completely off the ground while it moves. This is done to reduce the heat taken in from the ground, as well as to increase the air flow over the belly to cool itself further.