| Pogona vitticeps | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Lacertilia |
| Family: | Agamidae |
| Genus: | Pogona |
| Species: | P. vitticeps |
| Binomial name | |
| Pogona vitticeps Ahl, 1926 |
|
Pogona vitticeps, the Central (or Inland) Bearded Dragon, is a species of agamid lizard occurring in a wide range of arid to semi-arid regions of Australia. This species is very popularly kept as a pet and exhibited in zoos.
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Adults of this species usually grow to be about 2 feet in length, with the tail accounting for over half of the total body length. Sexes are not strongly dimorphic, but males can be distinguished from females as they have a wider cloacal opening, the base of the tail is wider, the head is usually larger with a larger beard (often black) and males possess hemipenes.[1] Bearded dragons come in a wide variety of colours, including brown, grey, reddish-brown, red, yellow, white, orange, and sometimes green. They are capable of undergoing very slight 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 these characteristics appear similar to a human beard. Males typically have a darker "beard" than females, and during mating season and courtship the "beard" 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.
Pogona vitticeps was first described by Ernst Ahl in 1926, placing it in the genus Amphibolurus.[2] [3]
This dragon is native to the semi-arid woodland, arid woodland, and rocky desert regions of Central Australia. They are skilled climbers, and often spend just as much time perching on tree limbs, fenceposts, and in bushes as they do on the ground. They spend the morning and early evening sunning themselves on an exposed branch or rock, and retreat to shady areas or underground burrows during the hottest parts of the afternoon.
Bearded dragons do not vocalize, except to hiss softly when threatened. Instead, they communicate through color displays, posture, and physical gestures like arm waving and head bobbing. Bearded dragons are not social animals, but will sometimes gather in groups, especially in popular feeding or basking areas. At these times, a distinct hierarchy will emerge: the highest-ranking animals will take the best - usually the highest or sunniest - basking spots, and all other individuals arrange themselves lower down. If a low-ranking animal tries to challenge one of the dominant dragons, the dominant animal will demonstrate its superiority by bobbing its head and inflating its beard, at which point the challenger may signal submission by waving one of its forearms in a slow circle. If the low-ranking dragon does not submit, it will return the head-bob, and a standoff or fight may ensue.
There are several different kinds of head bob gesture. These are:
- Slow bowing motion - often used by adult females to signal submission to a male.
- Fast bob - used by males to signal dominance (often accompanied by an inflated and/or blackened beard).
- Violent bob - used by males just before mating. This bob is much more vigorous, and usually sets the animal's whole body in motion.
The male will only arm wave to show submission to a dominant male, whereas the female will arm wave to show that she is ready to mate followed by a slow head bob. Gravid females will often refuse the advances of a male by chasing him and lying on his back.
When under direct attack, the Central bearded dragon opens the mouth to display its yellow membranes and extend their beard.[4] They darken the colour of their skin and flatten their bodies, and will hiss and make small jumps towards their attacker.[5]
The age of sexual maturity has not been measured although it is estimated to be approximately two or three years.[6] Body size and growth rates are more important than age when determining sexual maturity in bearded dragons.[7] Males will become very aggressive towards each other and will assert their dominance by inflating their beards and through fast head bobbing. Breeding typically occurs in the early spring. Females will lay a clutch of eleven to thirty oblong-shaped eggs in a shallow nest dug in the sand. After being laid the eggs are buried and are left unattended. The eggs will hatch approximately 60 to 80 days later depending on the incubation temperature. In captivity, they can be incubated in a styrofoam fish box, but without a male lizard the eggs the female lay will not be fertile. However a female bearded dragon can retain sperm, and thus produce fertile eggs even after being separated from a male.
Bearded Dragon courtship involves the male "head bobbing" to display dominance. If the female displays submissive behavior the male will use its mouth to grab the back of the females head and the male will also wrap its front legs around the females upper torso to keep her from moving. Copulation and insemination doesn't take very long. The gestation period averages about a month and a half.
Several of the Pogona genus are bred in captivity as pets, the two most popular are this species, Pogona vitticeps, and the Western Bearded Dragon (Pogona minor subspecies).[8][9] The bulk of captive bred Bearded Dragons today are thought to have originated from stock illegally exported from Australia during the 1970s. [10]
Captive Bearded Dragons world wide are threatened by Agamid adenovirus, a virus that when showing symptoms compromises the immune system of the dragon, and leads to death from other diseases, however majority of the infections are sub-clinical. Sub-clinically infected animals show no signs themselves but are active carriers of the disease and will infect other Bearded Dragons.
When the female is ready to lay eggs she will generally stop eating and spend most of her time trying to dig.