{{Short description|Genus of lizards known as bearded dragons}} {{Use dmy dates|date=May 2017}} {{Automatic taxobox | image = Eastern Bearded Dragon, Majura, ACT 2609, Australia imported from iNaturalist photo 67070853 (cropped).jpg | image_caption = Eastern bearded dragon ''(P. barbata)'' | image2 = | image2_caption = | taxon = Pogona | authority = Storr, 1982<ref>Wells, Richard W.; Wellington, C. Ross. 1985. "A Classification of the Reptilia and Amphibia of Australia". ''Australian J. Herp. Suppl. Ser.'' (1): 1–61. (Genus ''Pogona'', p. 19).</ref> | type_species = ''Agama barbata'' | type_species_authority = Cuvier 1829 | subdivision_ranks = Species | subdivision = *''Pogona barbata'' *''Pogona henrylawsoni'' *''Pogona microlepidota'' *''Pogona minor'' *''Pogona mitchelli'' *''Pogona nullarbor'' *''Pogona vitticeps'' }} '''''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,<ref>{{cite web |title=8 Reasons For Your Bearded Dragonś Black Beard |url=https://beardeddragontank.com/8-reasons-for-your-bearded-dragons-black-beard |website=beardeddragontank.com}}</ref> 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.<ref>{{Cite web|url=http://beardeddragoncaresheet.weebly.com/housing.html|title=Housing|website=Care of Bearded Dragons (Pogona vitticeps)|access-date=2019-12-19}}</ref> ''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.<ref name="Browne-Cooper">{{cite book |last=Browne-Cooper |first= Robert|author2=Brian Bush |author3=Brad Maryan |author4=David Robinson |title= Reptiles and Frogs in the Bush: Southwestern Australia|year= 2007|publisher= University of Western Australia Press|isbn= 978-1-920694-74-6 |page=160|quote=''Pogona minor minor'', Abrolhos Bearded Dragon }}</ref>

== Description == thumb|upright=0.5|right|Captive adult measuring over 30 cm (1 ft) thumb|right|Galore Hill Nature Reserve, New South Wales, Australia [[File:Bearded Dragon Skeleton.jpg|thumb|Skeleton at the Museum of Osteology in Oklahoma City, Oklahoma, United States]] 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<ref>{{Cite web |last=Pets |first=Lizard |date=May 23, 2023 |title=Why do bearded dragons bob their heads at humans? |url=https://lizard-pets.com/behaviour/why-do-bearded-dragons-bob-their-heads-at-humans/ |website=Lizard Pets}}</ref> 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 {{convert|60|cm|in|abbr=on}} long, and females up to {{convert|51|cm|in|abbr=on}}.

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.<ref>{{Cite journal |last1=Chandrasekara |first1=Uthpala |last2=Mancuso |first2=Marco |last3=Sumner |first3=Joanna |last4=Edwards |first4=Dan |last5=Zdenek |first5=Christina N. |last6=Fry |first6=Bryan G. |date=2024-08-01 |title=Sugar-coated survival: N-glycosylation as a unique bearded dragon venom resistance trait within Australian agamid lizards |journal=Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology |volume=282 |article-number=109929 |doi=10.1016/j.cbpc.2024.109929 |issn=1532-0456|doi-access=free }}</ref>

== Habitat == Bearded dragons live in the woodlands, heaths, deserts and coastal dunes,<ref>{{cite journal|author1=Yang, R.|author2=Brice, B.|author3=Ryan, U.|year=2016|title=Morphological and molecular characterization of ''Choleoeimeria pogonae'' n. sp. coccidian parasite (Apicomplexa: Eimeriidae, 1989, Paperna and Landsberg) in a western bearded dragon (''Pogona minor minor'')|journal=Experimental Parasitology|volume=160|pages=11–16|doi=10.1016/j.exppara.2015.11.001|pmid=26586629 }}</ref> with their range extending throughout the interior of the eastern states to the eastern half of South Australia and southeastern Northern Territory.<ref>{{Cite web|url=https://australianmuseum.net.au/central-bearded-dragon|title=Central Bearded Dragon – ''Pogona vitticeps'' – Australian Museum|website=australianmuseum.net.au|language=en|access-date=2018-04-19}}</ref> 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.<ref>{{Cite web|title = Bearded Dragon (''Pogona'') Species Profile: Habitat, Diet, and Care|url = http://www.peteducation.com/article.cfm?c=17+1796&aid=2730|website = www.peteducation.com|access-date = 2015-09-23|archive-url = https://web.archive.org/web/20150529032737/http://www.peteducation.com/article.cfm?c=17+1796&aid=2730|archive-date = 29 May 2015}}</ref>

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.<ref>''Mayer, William Vernon. “Dormancy.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 17 May 2016, www.britannica.com/science/dormancy#ref1121981.''</ref> Bearded dragons go through brumation when the temperature goes below 15.5–21.0&nbsp;°C (60–70&nbsp;°F) during the night and 24.0–26.5&nbsp;°C (75–80&nbsp;°F) during the day for 8–10 hours.<ref>Vosjoli, Philippe De. ''The Bearded Dragon Manual: Expert Advice for Keeping and Caring for a Healthy Bearded Dragon''. 2nd ed., Lumina Media, 2016.</ref> When the climate is too hot they will often burrow underground.<ref>{{Cite web|title = Why Do Bearded Dragons Burrow? – Online Bearded Dragon Care|date = 21 September 2015|url = http://www.onlinebeardeddragoncare.com/do-bearded-dragons-burrow/|access-date = 2015-09-23}}</ref> They will also form more permanent burrows or covered hiding places to use as protection from the climate changes at night and predation.<ref>{{Cite journal|last=Doneley|first=Bob|title=CARING FOR THE BEARDED DRAGON|url=https://www.cabi.org/ISC/FullTextPDF/2006/20063121821.pdf|journal=Exotics — Reptiles and Amphibians}}</ref>

== Species == The following six species are recognised as being valid.<ref>{{cite web|title="IUCN search Pogona – Genus"|url=https://www.iucnredlist.org/search?taxonomies=170418&searchType=species}}</ref> {| class="wikitable" |+ !Species !Common name |- |''Pogona barbata'' {{small|(Cuvier, 1829)}} |eastern bearded dragon |- |''Pogona henrylawsoni'' {{small|(Wells & Wellington, 1985)}} |Rankin's dragon, Lawson's dragon, black-soil bearded dragon, dumpy dragon, dwarf bearded dragon |- |''Pogona microlepidota'' {{small|(Glauert, 1952)}} |Kimberley bearded dragon, Drysdale River bearded dragon |- |''Pogona minor'' {{small|(Sternfeld, 1919)}} |western bearded dragon, dwarf bearded dragon |- |''Pogona nullarbor'' {{small|(Badham, 1976)}} |Nullarbor bearded dragon |- |''Pogona vitticeps'' {{small|(Ahl, 1926)}} |central bearded dragon, inland bearded dragon |} ''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.<ref>{{Cite web |date=2019-06-20 |title=Bearded dragons |url=https://www.nationalgeographic.com/animals/reptiles/facts/bearded-dragon |access-date=2024-02-29 |website=Animals |language=en}}</ref>

Correspondingly, adult male bearded dragons can bite more forcefully than adult females, which is associated with greater head dimensions.<ref>{{cite journal | title = Reproductive phenotype predicts adult bite-force performance in sex reversed dragons (''Pogona vitticeps'') | journal = Journal of Experimental Zoology A | volume = 333 | pages = 252‒263 | year=2020 | author= Jones MEH, Pistevos JC, Cooper N, Lappin, AK, Georges A Hutchinson MN, Holleley CE. | issue = 4 | doi=10.1002/jez.2353 | pmid = 32061035 | bibcode = 2020JEZA..333..252J | hdl = 10141/622643 | s2cid = 211122728 | hdl-access = free }}</ref>

thumb|Bearded dragon with mouth agape The bearded dragon occurs in many different colors. The beard itself is used for mating and aggression displays, as well as heat management. It forms part of a range of gestures and signals through which the dragons have basic levels of communication. Both sexes have a beard, but males display more frequently, especially in courtship rituals. Females also display their beards as a sign of aggression. The beard darkens, sometimes turning jet black, and inflates during the display. The bearded dragon may also open its mouth and gape in addition to inflating its beard to appear more intimidating. Extreme behavior such as hissing can be observed when threatened with a predator, inflating the body and tilting towards the threat in defense. Bearded dragons have relatively strong jaws, but often only attack as a last resort when threatened outside of competition with their own species.

Head bobbing is another behavior seen in both females and males; they quickly move their heads up and down, often darkening and flaring their beards. Changes in the pace of head bobbing are thought to be a form of communication. Males head bob to impress females, and a male often has to demonstrate his dominance when attempting to mate before the female will concede. Smaller males often respond to a larger male's head bobbing by arm waving, which is a submissive sign. Females also arm wave to avoid aggression, often in response to a male's head bobbing.<ref>{{cite web |author=Periat, Jennifer (Pat. J.) |title=''Pogona vitticeps'' central bearded dragon |date=17 February 2000 |editor=Harding, James |website=Animal Diversity Web |url=https://animaldiversity.org/accounts/Pogona_vitticeps/ |access-date=27 June 2020}}</ref> Female bearded dragons have been seen lowering themselves towards the ground and intermittently arm waving whilst moving away from a dominant male in an attempt to either appease or escape.

The bearded dragon has also been shown to perceive illusion, specifically the ''Delboeuf illusion''. In an experiment at the University of Padova, bearded dragons were presented with two different-sized plates with the same amount of food.<ref>{{cite journal |author1=Santacà, M. |author2=Miletto Petrazzini, M. E. |author3=Agrillo, C. |author4=Wilkinson, A. |year=2019 |title=Can reptiles perceive visual illusions? Delboeuf illusion in red-footed tortoise (''Chelonoidis carbonaria'') and bearded dragon (''Pogona vitticeps'') |journal=Journal of Comparative Psychology |volume=133 |issue=4 |pages=419–427 |doi=10.1037/com0000176 |pmid=30896231 |s2cid=84842383 }}</ref> The bearded dragons chose the smaller plate more often than they chose the larger one, showing that they were able to perceive the illusion and interpret that a larger plate does not always mean more food. This is the first evidence of this behavior being shown in a reptile species.

== Reproduction == When brumation comes to an end, the male bearded dragon goes out to find a mate. A courtship ritual occurs where the male starts bobbing his head, waving his arms, and stomping his feet in front of the female. The male chases the female and bites the back of her neck and holds on while he gets in position to copulate.<ref>Green, Darren. ''Keeping Bearded Dragons Pogona Species''. Australian Reptile Keeper, 2009.</ref>

During the breeding period, female bearded dragons can store sperm in their oviductal crypts.<ref>Amey Andrew P. Whittier Joan M. (2000) The annual reproductive cycle and sperm storage in the bearded dragon, Pogona barbata. ''Australian Journal of Zoology'' 48, 411–419.</ref> This allows the females to lay a clutch of 11–30 eggs, twice from one mating.<ref>Hosking, Chris. “Australian Museum.” ''Central Bearded Dragon - Pogona Vitticeps'', 2 May 2017, australianmuseum.net.au/central-bearded-dragon.</ref>

Bearded dragons exhibit temperature sex determination; while the embryo is developing, higher temperatures cause dragons with a male genotype to experience sex reversal and express a female phenotype. This produces a bearded dragon that is a female, but still has a male genotype. Incubation temperatures above {{Convert|31|C}} can cause sex reversal, and the likelihood of sex reversal has a positive correlation with temperature up to 36&nbsp;°C. Incubation temperatures below 31&nbsp;°C cannot trigger sex reversal.<ref>{{cite journal |last1=Castelli |first1=Megan |last2=Georges |first2=Arthur |title=Evolving thermal thresholds explain the distribution of temperature sex reversal in an Australian dragon lizard |journal=Diversity and Distributions |date=4 November 2020 |volume=27 |issue=3 |pages=427–438 |doi=10.1111/ddi.13203 |doi-access=free |hdl=1885/274579 |hdl-access=free }}</ref> Surprisingly, female bearded dragons with a male genotype do not have many differences from genotypic females. According to one study done on bite force, male bearded dragons have a higher bite force than genotypic females, and sex-reversed females, but no difference was seen between genotypic females and sex-reversed females.<ref>{{cite journal |last1=Jones |first1=Marc |last2=Pistavos |first2=Jennifer |last3=Cooper |first3=Natalie |last4=Lappin |first4=AK |last5=Georges |first5=Arthur |title=Reproductive phenotype predicts adult bite-force performance in sex-reversed dragons (Pogona vitticeps) |journal=Journal of Experimental Zoology A |date=April 2020 |volume=333 |issue=4 |pages=252–263 |doi=10.1002/jez.2353|pmid=32061035 |doi-access=free |bibcode=2020JEZA..333..252J |hdl=10141/622643 |hdl-access=free }}</ref>

Like many other reptile species (and what is most often observed in birds), females are capable of laying eggs even without fertilization. These eggs appear slightly smaller and softer, and contain a yellow yolk when broken open.

=== Congenital defects === During the development of an embryo, abnormalities may result in birth defects. These abnormalities might be caused by chromosomal disorders, chemicals, or other genetic or environmental factors.

* Bicephalism is when a bearded dragon is born with two heads and one body.<ref name="Brown">Brown, Danny. ''A Guide to Australian Dragons in Captivity''. ABK Publications, 2012</ref> * Anasarca is when a bearded dragon is swollen within the egg. Observing eggs in the incubator, an anasarca egg appears to be sweating. The cause of this is not known.<ref name="Brown" /> * Shistosomus reflexa is when the organs of a bearded dragon develop outside of the body.<ref name="Brown" /> * Spinal and limb defects are abnormalities in the spine, tail, limbs, or toes. This occurs with nutritional deficiencies, trauma, or temperature issues during the development of the affected area.<ref name="Brown" /> * Microphthalmia/anophthalmia is when a bearded dragon is born with small or no eye(s). The cause of this defect is a traumatic event or an environmental event that occurred during the development of the eyes.<ref name="Brown" /> * Hermaphroditism is when the reproductive organs of both male and female are present. Bearded dragons born with both reproductive organs are infertile.<ref name="Brown" /> *Tail Necrosis/Tail rot is a serious condition in which the bearded dragon's tail starts to rot and blacken. It is caused by tail injury, blood clot, or shedding complications, and can kill the bearded dragon.<ref name="Brown" />

== In captivity == thumb|Through selective breeding, bearded dragons can have various colors and patterns. The central bearded dragon is the most common species in captivity, as well as one of the most popular pet reptiles,<ref name="Valdez 676">{{Cite journal |last=Valdez |first=Jose W. |date=March 2021 |title=Using Google Trends to Determine Current, Past, and Future Trends in the Reptile Pet Trade |journal=Animals |language=en |volume=11 |issue=3 |pages=676 |doi=10.3390/ani11030676 |doi-access=free |pmid=33802560 |pmc=8001315 |issn=2076-2615}}</ref> with some smaller species such as ''Pogona henrylawsoni'' being used as substitutes where less housing space is available. Introduced into the U.S. as pets during the 1990s, bearded dragons have gained much popularity as an exotic pet.<ref name="Valdez 676"/> This popularity has been sustained, even after Australia banned the sale of its wildlife as pets in the 1960s.<ref>{{cite web|title=Exports of Australian native plants and animals|access-date=19 March 2018|url=http://www.environment.gov.au/biodiversity/wildlife-trade/law#Exports_of_Australian_native_plants_and_animals|publisher=environment.gov.au}}</ref>

Generally, the bearded dragon is a solitary animal. Males are usually housed alone, as they fight with other males and breed with females. Captive adults reach about {{convert|40|to|61|cm|in|abbr=on}} from head to tail, weigh {{convert|290|to|600|g|-1|abbr=on}}<ref>{{cite web|url=http://www.hadesdragons.co.uk/caresheet.html|title=Hades Dragons|year=2010|access-date=13 August 2013|publisher=hadesdragons.co.uk|archive-url=https://web.archive.org/web/20131105174244/http://www.hadesdragons.co.uk/caresheet.html|archive-date=5 November 2013|df=dmy-all}}</ref> and live for about 10 to 15 years and longer with good care.<ref name="Browne-Cooper" /> They have been known to live up to about 15 years in captivity, and the current world record is 18 years.<ref>{{Cite news|url=http://www.guinnessworldrecords.com/world-records/116317-oldest-bearded-dragon-ever|title=Oldest bearded dragon ever|work=Guinness World Records|access-date=2018-08-12|language=en-GB}}</ref>

Through selective breeding, many different versions of the central bearded dragon have been developed, referred to as "morphs". They have a few main genetic traits, including "hypomelanism" and "translucent", which refer to traits physically displayed by the dragon. Bearded dragons with hypomelanism often tend to have lighter and more vibrant coloration. Translucents have a less opaque quality to their skin, making their colors seem stronger, and have black eyes. Also, "leatherbacks" have reduced scale texture to give a smoother skin, "silkbacks" have softer outer skin, and "German giants" are larger than average. Silkbacks in particular require special care, as they have far more delicate skin, and as such, require different UV and humidity requirements. They also tend to live shorter lives.<ref>{{Cite web |title=Bearded Dragon |url=https://bewildnc.org/bearded-dragon/ |access-date=2022-11-24 |website=BeWild Reptile Rescue}}</ref> <!-- nonencyclopedic how-to === Captive diet === [[File:BeardedDragonEatting.jpg|thumb|right|Bearded dragon eating dandelion leaves]] Juvenile and baby bearded dragon diets consist mainly of insects, and they require substantial amounts of protein. A juvenile bearded dragon eats insects three times a day on average. After a few feedings, the dragon's usual appetite can be determined.<ref name="Big Al's Pets">{{cite web |title=Bearded Dragon Care |date=December 2014 |access-date=14 January 2015 |url=http://www.bigalspets.com/resources/cat/reptiles/post/bearded-dragon-diet/ |publisher=Big Al's Pets |archive-url=https://web.archive.org/web/20150128132902/http://www.bigalspets.com/resources/cat/reptiles/post/bearded-dragon-diet/ |archive-date=28 January 2015 |df=dmy-all }}</ref> Crickets and dubia roaches are the most popular insects fed to bearded dragons, but they can also be fed other insects such as black soldier fly larvae, spiders, locusts, superworms, silkworms, butterworms, fruit flies, grasshoppers, mealworms and hornworms. Bearded dragons also eat increasing amounts of plant-based food as they grow; adults should have a diet consisting primarily of plant matter, the most important of which are leafy greens.<ref>Bearded Dragon Food Pyramid 15 April 2016. Complete Critter. http://www.completecritter.com/bearded-dragon.html</ref> Spring greens, endive, kale,<ref>{{Cite web|title = Can Bearded Dragons Eat Kale? When And How Much|date = 21 September 2015|url = https://allourcreatures.com/can-bearded-dragons-eat-kale/|access-date = 2021-04-24}}</ref> rocket, Chinese leaf, and watercress are all suitable vegetables, as are butternut squash, pea shoots, bell peppers, and many other plants.

It is important to check before feeding something new to a bearded dragon, as some things can be toxic to them or will act to bind calcium in their diet, preventing them from being able to absorb calcium. The main things to avoid often contain oxalates and goitrogens.<ref>{{Cite web |title=Bearded Dragons - Feeding {{!}} VCA Animal Hospital |url=https://vcahospitals.com/know-your-pet/bearded-dragons-feeding |access-date=2023-01-25 |website=Vca |language=en}}</ref> This diet is also seasonal, meaning that it changes with the availability of live prey in the wild. Studies of wild ''Pogona vitticeps'' have shown that termites comprise over 60% of the stomach contents of those studied. Bearded dragons, like many reptiles, are opportunistic and will binge feed on live food sources where available, preferring live prey over plant matter. Bearded dragons also require supplements to stay healthy, including calcium, vitamin D, and a multivitamin. These supplements are typically powdered and are administered by dusting their food with them.<ref>{{Cite web|url=https://beardiebungalow.com/bearded-dragon-supplements/|title = Supplements for Your Bearded Dragon, A Helpful Guide| date=August 2019 }}</ref> --> === Common health issues === Although bearded dragons are fairly resilient to illness, improper care can potentially kill a bearded dragon. Some health issues that bearded dragons may have include metabolic bone disease,<ref>{{Cite web |date=July 2019 |title=Metabolic Bone Disease MDB |url=https://beardeddragonsworld.com/legs-not-working-nshp-mbd/ |access-date=21 May 2022 |website=Bearded Dragons World}}</ref> adenovirus, impaction, polarisation, dystocia,<ref>{{Cite web |date=1 Jan 2020 |title=Bearded Dragon Egg Bound |url=https://beardeddragonsworld.com/bearded-dragon-egg-bound |access-date=21 May 2022 |website=Bearded Dragons World}}</ref> Yellow Fungus Disease<ref>{{Cite web |date=July 2019 |title=Yellow Fungus Disease |url=https://beardeddragonsworld.com/yellow-skin-fungus/ |access-date=21 May 2022 |website=Bearded Dragons World}}</ref> and parasites. The majority of health issues bearded dragons face in captivity are due to poor diet and inadequate heat and lighting.<ref>{{Cite web|title=Bearded Dragons – Diseases|url=http://vcahospitals.com/know-your-pet/bearded-dragons-diseases|access-date=2021-06-14|website=vca_corporate}}</ref>

==== Metabolic bone disease ==== Metabolic bone disease (MBD) is a collective term for several common diseases/illnesses that can be fatal and is probably the most common health problem of bearded dragons.<ref>{{Cite journal |last1=Schmidt-Ukaj |first1=S. |last2=Hochleithner |first2=M. |last3=Richter |first3=B. |last4=Hochleithner |first4=C. |last5=Brandstetter |first5=D. |last6=Knotek |first6=Z. |date=2017-09-20 |title=A survey of diseases in captive bearded dragons: a retrospective study of 529 patients |url=http://www.agriculturejournals.cz/web/vetmed.htm?volume=62&firstPage=508&type=publishedArticle |journal=Veterinární Medicína |volume=62 |issue=9 |pages=508–515 |doi=10.17221/162/2016-VETMED|doi-access=free }}</ref> A main attribute of MBD is the weakening of the skeletal structure and possible deformation. It occurs in bearded dragons due to malnutrition or the use of improper lighting, meaning they are unable to properly assimilate calcium from their diet or there isn't enough in their diet. Most bearded dragons in captivity will be fed supplementation and all will need a UVB light to enable them to properly use calcium in their diet. Typical foods that bearded dragons eat, including kale, mustard greens, and collard greens, are high in calcium and should be eaten daily along with other leafy greens and vegetables to have a well-balanced diet.<ref>{{Cite web|url=http://www.beautifuldragons.com/MBD.html|title=MBD – Metabolic Bone Disease |website=Beautiful Dragos Reptile Rescue |access-date=2017-05-04}}</ref> Bearded dragons require UVB lights to process calcium in their diet. Without processing this calcium, their bodies will use calcium from their bones, therefore weakening them. Symptoms seen in bearded dragons with MBD include bumps in the legs, twitches or tremors, bumps along the spine or tail, a swollen bottom jaw, and jerky movements.

==== Hypocalcemia ==== Hypocalcemia occurs when there are low levels of calcium in the bearded dragon's blood. Hypocalcemia is most often tied to metabolic bone disease. Low levels of calcium can result in twitching muscles, or seizures. Hypocalcemia is most often seen in young bearded dragons, as they are slightly more fragile than adults. Maintaining a diet that consists of enough calcium is crucial to avoiding hypocalcemia as well as metabolic bone disease.<ref>{{Cite web|url=http://www.triciaswaterdragon.com/calciumdeficiency.htm|title=Calcium Deficiency |website=Tricia's Chinese Water Dragon, Reptile and Amphibian Care Page |author=Tricia Power |date=1995–2012 |language=en|access-date=2017-05-05}}</ref>

==== Impaction ==== Impaction occurs often in bearded dragons when they are fed food that is too big for them. Bearded dragons will try to eat worms or crickets that are too big for them, but this can be extremely harmful. Food should not be bigger than the space between their eyes for a young dragon. Older dragons can generally cope with larger insects but not oversized prey. If a dragon eats food that is too big for it, pressure will be put on its spinal cord during digestion. This pressure can lead to impaction which can lead to death. <ref>{{Cite web |date=2020-06-26 |title=Does Loose Substrate Cause Impaction in Bearded Dragons and Other Reptiles? |url=https://reptifiles.com/does-loose-substrate-cause-impaction/ |access-date=2026-03-20 |language=en-US}}</ref>

==== Upper respiratory infection (URI) ==== In bearded dragons, respiratory infection (RI) is caused by a bacterial infection in the lungs. Bearded dragons develop a [https://mybeardies.com/bearded-dragon-respiratory-infection/ respiratory infection] due to a number of reasons such as incorrect lighting and temperature, high humidity, prolonged psychological stress, and poor captive conditions.

==== Atadenovirus ==== Atadenovirus (ADV), also referred to as adenovirus, can be deadly. ADV can be spread between reptiles through contact alone. Most juvenile ADV-positive bearded dragons do not live past 90 days. While ADV-positive adults will live longer, they eventually contract liver diseases.<ref>{{Cite web|url=http://www.reptilesmagazine.com/Reptile-Health/Habitats-Care/Atadenovirus-This-Disease-Can-Be-Deadly-To-Your-Bearded-Dragon/|title=Atadenovirus – This Disease Can Be Deadly To Your Bearded Dragon|website=www.reptilesmagazine.com|date=27 January 2012 |language=en|access-date=2017-05-05|archive-url=https://web.archive.org/web/20170522032024/http://www.reptilesmagazine.com/Reptile-Health/Habitats-Care/Atadenovirus-This-Disease-Can-Be-Deadly-To-Your-Bearded-Dragon/|archive-date=22 May 2017}}</ref> Common symptoms of ADV-positive bearded dragons include stunted growth and slow weight gain. Because of their compromised immune systems, ADV-positive bearded dragons may be infected with intestinal parasites.<ref>{{Cite web|url=http://azeah.com/lizards/atadenovirus-bearded-dragons|title=Atadenovirus in Bearded Dragons|last=Bjornebo|first=Heather|date=2016-08-11|website=azeah.com|access-date=2017-05-05}}</ref>

=== Lighting === thumb|A bearded dragon in a pet store, with artificial lighting above Bearded dragons require UVB to enable vitamin D<sub>3</sub> synthesis and to prevent illnesses like metabolic bone disease.<ref>{{Cite web |title=Pet Reptiles Need Vitamin D and Calcium for Bone Health |url=https://aces.illinois.edu/news/pet-reptiles-need-vitamin-d-and-calcium-bone-health |access-date=2022-05-21 |website=College of Agricultural, Consumer & Environmental Sciences |language=en}}</ref> Vitamin D<sub>3</sub> is essential to calcium absorption, with calcium playing a major role in various critical biological functions. Bearded dragons also require UVA, which stimulates feeding, breeding, basking and overall health. They also require a basking heat source, most commonly a light-emitting source, to provide a basking area. Heat and UV are both vital to the bearded dragons' biological function.

== Gallery == <gallery> File:Juvenile bearded dragon.jpg|3-month-old bearded dragon File:Beardeddragon.jpg|Male basking under a lamp File:Pogona vitticeps infant on rock.jpg|''Pogona'' infant File:Bearded Dragon mugshot.jpg|A male bearded dragon File:Fancy Bearded Dragon (pogona) in grass.jpg </gallery>

== See also == * ''Chlamydosaurus'' * Leopard gecko

== References == {{Reflist|30em}}

== Further reading == *Storr GM. 1982. "Revision of the Bearded Dragons (Lacertilia: Agamidae) of Western Australia with Notes on the Dismemberment of the Genus ''Amphibolurus'' ". '' Rec. Western Australia Mus.'' '''10''' (2): 199–214. (''Pogona'', new genus, p.&nbsp;201).

== External links == {{Wikispecies}} {{Commons category}} *{{NRDB genus|genus = Pogona}}

{{Taxonbar|from=Q743973}} {{Authority control}}

Category:Pogona Category:Lizard genera Category:Agamid lizards of Australia Category:Taxa named by Glen Milton Storr Category:Reptiles as pets Category:Taxa described in 1982