Bearded Dragon

From Wikipedia, the free encyclopedia

Bearded Dragon is the common name for any agamid lizard in the genus Pogona. They are native to Australia.

Bearded Dragons are popular exotic pets in many places, notably the species Pogona vitticeps, the Inland or Central Bearded Dragon. These pets are also affectionately called "Beardies" by those who breed or raise them. They are a popular breed among children, because of their friendly and calm nature, along with the relitively easy care arrangements.

Contents 1 Characteristics 2 Feeding 2.1 Poisonous/Dangerous Foods 3 Housing 4 Personality 5 Breeding 6 Diseases 7 Gallery 8 References 9 Further reading 10 External links

[edit] Characteristics

Bearded Dragon have broad triangular heads and flattened bodies, with adults reaching approximately 18 to 24 inches head-to-tail they can live typically 8–15 years ^[1]. When threatened, they will expand a spiny pouch under their jaw, as well as inhale air and puff up to make them appear larger. The pouch resembles a beard, lending the animal their name. Males are often slightly larger than females and have a black pouch under their jaw unlike the females, with a broader head in proportion to their bodies, but females are often slightly more heavily set. Bearded Dragons have a distinctive series of lateral spines (specialized scales) radiating horizontally from the head to the base of the tail. Their color ranges from light tan to dark brown, depending on their native soil, often with highlights of black, brilliant red, or gold, and can change somewhat depending upon their internal condition, mood or temperature [darkening when cool]. Some captive populations have been selectively bred for more brilliant colorations. As juveniles, they are semi-arboreal. As adults, they are more terrestrial, but will climb to bask and search for prey. Bearded Dragons can occupy a large range of habitats from the desert to dry forests and scrublands ^[2]

All species are from Australia, but they have been exported worldwide and bred successfully in captivity. In the wild, the various species are widely distributed throughout different regions of Australia. Bearded Dragons live about 8–15 years with proper care in captivity, though some can live up to 20 years old^[3].

Bearded Dragons are opportunistic omnivores. Many Bearded Dragon habitats are dry and sparsely vegetated, so food may often be difficult to find. As a result, Bearded Dragons are capable of subsisting on a wide variety of food sources.

Their stomachs are large enough to accommodate large quantities of food. Young Bearded Dragons do not eat as much vegetation as their adult counterparts. As a Bearded Dragon ages it may be persuaded to eat less animal matter and more plants, maybe levelling off at around an 80% plant and 20% animal diet^[4].

Due largely to their animated and highly social behavior, mild temperament, willingness to breed in captivity, flexible diet, and robust nature, Bearded Dragons are popular among reptile enthusiasts as pets.They make great pets for children because they are relatively friendly for reptiles.

[edit] Feeding

Bearded Dragons are omnivorous, requiring both insects and vegetable food. A typical diet for captive Bearded Dragons includes leafy greens and vegetables, and regular meals of feeder insects.

Popular feeder insects include crickets, roaches, locusts, silkworms, hornworms, butterworms, and phoenix worms^[5]. The mealworm has a fairly hard chitin (exoskeleton) and is generally low in the "chitin to meat" ratio, as well as having a poor phosphorous/calcium ratio, making it far less nutritious than other feeder insects^[6]. Chitin is hard enough that large amounts of it can cause impaction in the Bearded Dragon's digestion system, and can lead to death, especially in younger and smaller animals. Waxworms, and superworms can be given as a treat, but sparingly as in most cases as they are extremely fatty, and in some cases very addictive, although they can be useful in building-up an undernourished individual. The rule of thumb on feeder insects is that the food fed to the animal must not be larger than the space between the eyes; feeding something larger could make it hard for the animal to swallow the food and can lead to the aforementioned fatal impaction^[7].

A significant portion of the Bearded Dragon's diet may consist of leafy greens. Dragons enjoy many types of readily available greens, including: collard greens, Kale(recommended only given on occasion), cabbage, spring greens, escarole, turnip greens, mustard greens, romaine lettuce, dandelion greens, parsley, and carrot tops^[8]. It is also recommended that this portion of the Dragon's diet be supplemented with a variety of finely diced fruits, vegetables, and legumes. Feeding a mixture of these plants ensures a wider variety of nutrients, and variations in texture to aid digestion.

[edit] Poisonous/Dangerous Foods

Insects caught in the wild are not recommended, due to the increased risk of pesticide exposure and parasites. Fireflies and all other animals with bioluminescence chemicals^[9] can be fatal to Bearded Dragons.

Avocado and Rhubarb are lethal to Dragons as well as birds. Some greens, such as iceberg lettuce, are mostly water and can lead to diarrhea or malnutrition. Spinach contains high oxalates which bind to calcium and in large amounts can lead to metabolic bone disease. Kale and cabbage also contain oxalates, but the ability of oxalates to lower calcium absorption is relatively small and definitely does not outweigh the ability of oxalate-containing foods, such as kale and cabbage, to contribute calcium to the meal plan. If a bearded dragon's digestive tract is healthy, and it receives adequate UV light and temperatures, it will get significant benefits - including absorption of calcium - from calcium-rich food plants that also contain oxalic acid.

[edit] Housing

A 20 gallon (75 litre) vivarium is the bare minimum for a juvenile Bearded Dragon, however they will fast outgrow this within their first year. When provided with the proper habitat, temperatures, and UVB lighting, Bearded Dragons are hardy lizards. They are also pets who do their best to hide health problems when becoming ill (as do most reptiles). This is probably an instinctual behavior, since a sick Dragon in the wild would probably not live long. The most common diseases include Agamid adenovirus, mites, terminal ingestion, thermal burns, calcium deficiency or in severe cases even bone disease, impaction, hypovitaminosis A, respiratory infections, dehydration, stomatitis, internal parasites, coccidia and other parasites, dystocia (egg binding), and MBD[4].

For an adult the minimum is a 40 gallon (150 litre) breeder, though many breeders recommend a 55 gallon (200 litre) breeder instead^[10]. This allows the Dragon ample space to turn around, lie down, and run to and fro as it chooses.

Bearded Dragons bask most of the day, absorbing the heat they need to digest their food. It is important that there are at least one or two good basking spots in the Dragon's habitat. Rocks are preferable to logs as they hold heat better, though logs can also provide stimulation for the animal as they will climb up and down it^[4]. Any item taken from the outside must first be boiled or baked, however, to remove contaminants. Electric or battery powered heating devices such as HotRocks can cause stomach burns if they malfunction, so they are not widely recommended^[11]. A habitat should also include something the Dragon can hide under.

Bearded Dragons also need proper lighting. A UVB light is needed, with two options being available, Fluorescent strip bulbs or mercury vapor bulbs. These bulbs will need to be kept within 8 inches of the basking spot so your lizard can properly absorb the rays and need to be replaced every 6 months^[12]. Without a good UVB the Dragon will develop MBD and not eat as much. A Dragon needs between 12 and 14 hours of daylight; much less or more causes problems with their circadian rhythms and makes them lethargic and sick.^[13]

For heating, Bearded Dragons need bright white light during the day. At night a red light can be used, as it will provide heat and you will be able to see it, but it will not disturb the animal's sleep cycle. Under tank heaters are one option for keeping the tank warm at night when the heating lamp is off, while ceramic heat emitters are another^[12].

Temperature is one of the most important health factors. A Dragon needs the correct temperature to digest, so a good thermometer is essential. Analog, Round, stick-on, and other non-digital thermometers do not measure basking temperature properly as they do not measure the actual basking spot, just the temperature of the air or glass. A digital thermometer with a probe or an Infrared thermometer are two recommended types of thermometers^[14]. Temps need to be 40C-43C (105F-110F) [basking spot] during day and 15C-26C (60F-80F) at night (the higher end of this range for babies, the lower portion of the range for adult Dragons). If the dragons do not receive the proper heat they will become lethargic, and they will eat less. Eventually the lack of proper heating will become fatal.

Substrate is another very important factor in keeping a healthy Dragon. Babies and Juveniles are particularly at risk of impaction and are often kept on paper towels, as they are easy to dispose of and clean up after, and there is no risk of the baby ingesting substrate. Tile is another popular choice, as is reptile carpet. As the Dragon gets older it can be put on finely sifted play sand. Calcium sand is often used and widely recommended, but is also reported to be a cause of impaction due to 'clumping' in the gut if ingested, while play sand will pass straight through a well fed individual. Rabbit food pellets, made of alfalfa, are the recommended choice by most breeders as they are ingestable and also easy to clean. Walnut shells, wood chips, and anything else of that sort are never to be used. They are large, with sharp edges, and can be swallowed. They are not digestible, however, and will swell and clog the gut, causing a very painful and potentially fatal impaction^[4].

[edit] Personality

Bearded Dragons are known, according to many owners, to be very docile and trusting, yet at the same time, outgoing and curious lizards. If you scare them [typically by approaching from above] they may make a slight hissing sound, usually opening their mouth in a threatening gape display. Their behaviour includes body language such as head bobbing [as a signal of dominance or defiance, usually but not exclusively in the male] and front leg waving [a submissive acknowledgement]. It is not recommended to try and arouse this behavior, however, as it is territorial in nature.

Pogona vitticeps is one of the more docile and friendly lizard species in the lizard pet trade. Unlike many large Monitor lizards and smaller lizards like Anoles, some people who have encountered Bearded Dragons argue the reptiles actually enjoy human contact and to be handled by humans. However, it is widely accepted they are at best simply indifferent to human contact. Although they may assume a defensive position, they very rarely bite, scratch, or otherwise attack a human. They are likable and get the owner lots of attention, especially if you take them out and about for a walk (providing it isn't too cold) in fact civilians have been known to stop people and take pictures. As a result, Bearded Dragons are a suitable reptile for a house with children provided hands are washed after contact.

Bearded Dragons are territorial and may fight a tank mate if an argument arises. Pairs of any gender combination have been known to fight, resulting in some cases in death of one or both of the pair. Unless two males are cohabiting, trouble is unusual with proper husbandry.^[15]. Generally, well housed and fed Bearded Dragons will live very well together, and will clearly mope if separated.

Dragons may brumate, a period similar to a mammal's hibernation^[16]. The animal will become lethargic and not come out that often, eating less, if anything, for a period of two to three months. It's often a concern to those unfamiliar with it, as lethargy and lessened appetite usually mean illness. When brumation starts to happen, it's suggested to go to a veterinarian with a fresh fecal sample for inspection for illness and parasites. In captivity brumation is often induced [with fewer hours of light and lower temps] to promote breeding activity in the following spring.

[edit] Breeding

Due to selective breeding, Dragons have begun to exhibit rather distinctive colorations. These "designer" Dragons display brilliant hues of pastel oranges, violets, and reds^[17]. The most popular morph thus far has been the "Sand Fire" Dragon, which exhibits a bright red-orange color with black stripes. A more unusual sub-breed is the leatherback, and another of that is the silk-back. These Dragons have reduced or no scales respectively, creating a smoother appearance^[18]. Much like designer dogs, the price tags of these customized pets are many times the price of Dragons without a specific morph.

To sex a Dragon, one must hold the tail up and look above the cloaca, also known as the vent. Males have two hemipenal bulges just above it on either side, on the base of the tail, creating an hourglass shaped indent. Females have only a single bulge in the centre. Males are also known to have large femoral pores along the inner thigh^[19], although this is not as reliable an indicator. Dragons usually lay between twenty and thirty eggs at a time, but can lay up to 50 eggs a clutch^[20]. The female will attempt to dig a hole in preferably damp substrate to lay and subsequently bury the eggs. Females have been known to eat the eggs that were not fertilised. Eggs are usually incubated between 25'c and 30'c for 50–75 days, although much longer incubation periods have been known at lower temperatures. Higher temperatures are likely to kill the eggs. Hatchlings may take up to 24 hours to emerge from the egg, and will be consuming egg nutrients for two to three days before eating food. They will then need very small live food [e.g. pinhead crickets] and may eat finely chopped greens. Food should be dusted with 'calcium powder', and water should be sprayed or provided in a very shallow dish.

[edit] Diseases

When provided with the proper habitat, temperatures, and UVB lighting, Bearded Dragons are hardy lizards. They are also pets who do their best to hide health problems when becoming ill (as do most reptiles). This is probably an instinctual behavior, since a sick Dragon in the wild would probably not live long. The most common diseases include Agamid adenovirus, mites, terminal ingestion, thermal burns, calcium deficiency or in severe cases even bone disease, impaction, hypovitaminosis A, respiratory infections, dehydration, stomatitis, internal parasites, coccidia and other parasites, dystocia (egg binding), and MBD^[4].

[edit] Gallery

Central/Inland Bearded Dragon at the Henry Doorly Zoo	From central NSW.	Pogona vitticeps	Young Pogona vitticeps
Bearded Dragon picture	Group of Inland Bearded Dragons basking on a rock at the Indianapolis Zoo's desert exhibit.	Two domestic Bearded Dragons basking on a log	Female Bearded Dragon gaping to dissipate excess heat while basking
A male bearded dragon basking under a lamp, enjoying the heat.	Bearded dragons at Brisbane Forest Park in Brisbane, Queensland, Australia

[edit] References

[edit] Further reading

• Raymond Hoser (June 1997). Pogona - From an Australian Perspective.. Author's website. “paper from REPTILIAN MAGAZINE (UK), 5 (2), , pp. 27–41 (Online version)”

[edit] External links

• Information related to Bearded Dragon from Wikispecies.

• Media related to Bearded Dragon from the Wikimedia Commons.
• bio.miami.edu/caresheet
• bearded-dragons.com/forum
• beardeddragon.org
• Bearded Dragon Care