Pogona is a genus of reptiles containing eight lizard species, which are often known by the common name bearded dragons or informally (especially in Australia) beardies. The name "bearded dragon" refers to the underside of the throat (or "beard") of the lizard, which can turn black and become inflated for a number of reasons, most often as a result of stress, if they feel threatened, or are trying to entice a mate. They are a semiarboreal species, spending significant amounts of time on branches, in bushes, and near human habitation. Pogona species bask on rocks and exposed branches in the mornings and afternoons and sleep at night, making them a diurnal species. Their diet consists primarily of vegetation and some insects. They are found throughout much of Australia and inhabit environments such as deserts and shrublands.
Description
The genus Pogona is in the subfamily Amphibolurinae of the lizard group Agamidae. Bearded dragons are characterized by their broad, triangular heads, flattened bodies, and rows and clusters of spiny scales covering their entire bodies. When threatened, bearded dragons puff up their bodies and beards to ward off predators and make their somewhat dull spikes seem more dangerous. Bearded dragons display a hand-waving gesture to show submission (most often when acknowledging another bearded dragon's territory), and a head-bobbing display to show dominance between dragons. Some have the ability to slightly change color in response to certain stimuli including rivalry challenges between males and ambient temperature changes (e.g., turning black to absorb heat). Bearded dragons occur in a variety of colors including browns and blacks and morphs and can range from being all dark to completely white under controlled breeding conditions. Males grow up to 60 cm (24 in) long, and females up to 51 cm (20 in). Bearded dragons contain a unique N-glycoslation resistance mechanism, which is absent in other Australian agamids. Due to the distinct morphology of the species, bearded dragons are more resistant to neurotoxic elapid snakes, and thus displaying selective evolution.
Habitat Bearded dragons live in the woodlands, heaths, deserts and coastal dunes, with their range extending throughout the interior of the eastern states to the eastern half of South Australia and southeastern Northern Territory. They are considered to be semiarboreal and quite readily climb and bask at height. This is also linked to dominance behavior and competition for territory/basking areas. They can be found on fallen/broken trees, rocky outcrops, and bushes when basking. Many of the Australian locals have spotted bearded dragons on fence posts and elevated rocky areas. At night, they prefer to dig holes to sleep in, climb in trees, or submerge themselves in rocks and like to climb into the cracks and crevices of stones and caves. Bearded dragons go through a type of hibernation called brumation, in which like hibernation, reptiles go months without eating, but sporadically drink water. Reptiles go dormant in the hottest temperatures, but it differs from brumation during cooler temperatures. When temperatures are extreme, a very small range of temperatures exists through which the reptile's bodies can stay active and where their bodies cannot tolerate the extreme heat and they die. Bearded dragons go through brumation when the temperature goes below 15.5–21.0 °C (60–70 °F) during the night and 24.0–26.5 °C (75–80 °F) during the day for 8–10 hours. When the climate is too hot they will often burrow underground. They will also form more permanent burrows or covered hiding places to use as protection from the climate changes at night and predation.
Species The following six species are recognised as being valid.
Nota bene: A binomial authority in parentheses indicates that the species was originally described under a different binomial.
Behavior Adult bearded dragons are very territorial. As they grow, they establish territories in which displays of aggression and appeasement form a normal part of their social interactions. A dominant male adopts a dominant stance and sometimes readies himself for a fight to attack a male aggressor to defend territory or food sources, or in competition for a female. Any male approaching without displaying submissive behavior is seen as a challenge for territory. Aggressive males have even been known to attack females that do not display submissive gestures in return. Correspondingly, adult male bearded dragons can bite more forcefully than adult females, which is associated with greater head dimensions.
… excerpt ends here. Continue reading the full article.
