The Bearded Dragon (Pogona spp), a native of Australia, is now found worldwide as a popular pet. Anecdotal reports indicate that it is starting to surpass the Iguana as the preferred pet reptile in the United States. In Australia it is found widely distributed in the wild, although strict wildlife regulations mean that it is relatively uncommonly kept as a pet.
It is a member of the family Agamidae the dragon lizards – a group of lizards found throughout the western Pacific, Australia, Indo-Malaysia, Asia and Africa. This family is represented in Australia by the Bearded Dragon, water dragons, the Frilled Lizard and many other species. Most agamids are terrestrial, although a few are semi-arboreal. They are oviparous, usually laying their eggs in shallow burrows.
There are eight sub-species of Bearded Dragons:
a. P. barbata the Eastern Bearded Dragon; found on the eastern coast of Australia.
b. P. vitticeps the Central or Inland Bearded Dragon; found in western Queensland and New South Wales, eastern Northern Territory and eastern South Australia.
c. P. minor minor the Dwarf Bearded Dragon; found over much of Western Australia.
d. P. minor minima the Western Bearded Dragon; found down the western coast of Australia.
e. P. minor mitchelli the North-West Bearded Dragon; found in north-western Western Australiaacross into the Northern Territory.
f. P. nullabor the NullaborBearded Dragon; found in a small area on the Nullabor Plains on the border between Western Australia and South Australia.
g. P. microlepidota the Kimberley Bearded Dragon; found in a small pocket in the Kimberley area in the north of Western Australia.
h. P. henrylawsoni Lawson’s Dragon (Rankin’s Dragon, Black-soil Plains Bearded Dragon); found in north Queensland.
Sexing Bearded Dragons
Bearded Dragons, especially juveniles, can be difficult to sex. Although cloacal probing has been described by some, sex is usually determined by external physical characteristics and behavior.
|Base of tail||wide||narrow|
|Pre-anal and femoral pores||large||small|
|Head||Large, wide||Narrow, long|
|Hemipenes||May be everted||absent|
|Beard||Large, black in color||Smaller, not as black|
|Behaviour||Aggressive, dominant, display beard||Not as aggressive or dominant, more likely to arm wave (see below)|
Where the climate is suitable (ie. similar to the Dragon’s natural environment) Bearded Dragons are best kept outdoors, giving them access to natural sunlight and exercise. Requirements for an outdoor enclosure include:
a. The enclosure should be sited in a well-drained location;
b. As a minimum, a floor area of 8 feet sq. should be provided for up to 3 adults, with an additional 4 feet sq. for each additional dragon;
c. Walls should be of a solid material, high enough to prevent escape, and buried in the soil to prevent the lizards burrowing out and rodents burrowing in. Wire mesh walls can lead to rostral abrasions as the lizards rub their noses on it.
d. A wire mesh roof can prevent access by other animals, including cats and birds such as crows;
e. Enclosure ‘furniture’ (rocks, branches, etc) should not be positioned so as to provide the Dragon with an escape route;
f. Water bowls should be shallow with gentle sloping sides, allowing the Dragon escape should it fall in to the water;
g. Shade and shelter should be provided;
h. An area to brumate over winter should be provided this may be a hollow log or an artificial cave, but in some climates a layer of leaf or litter may be sufficient;
i. Only non-toxic plants should be provided. Rockery plants, grasses and clumping low vegetation are ideal. Avoid broad-leafed plants, as they tend to become very wet underneath their foliage;
In areas of high humidity or temperature extremes, it may be more suitable to keep Bearded Dragons indoors. While this allows more control over the Dragon’s environment, the lack of sunlight and exercise can become an issue. Requirements for an indoor enclosure include:
a. a large floor surface area is preferable to height. The minimum floor space for one dragon is 183cm (72″) x 41cm (16″) ;
b. walls should be of glass or sealed timber. Wire mesh walls can lead to rostral abrasion;
c. glass enclosures should be insulated on the base and on three sides to minimise heat loss;
d. a branch should be provided to allow the Dragon to climb;
e. substrates should be easily cleaned or replaced, and preferably of a material unlikely to be ingested. Rock and sand are commonly used, but are often associated with gastrointestinal problems. Newspaper, while visually unappealing, has major safety and hygiene advantages.
f. Heating, lighting and ventilation are essential (see below).
Ultraviolet light is necessary for Bearded Dragons for calcium metabolism. Wherever possible, this should be provided by natural sunlight, unfiltered by glass or plastic. Full spectrum fluorescent lights manufactured for reptiles should be placed no more than 30cms (12″) above the lizard, and changed every 6-8 months. Basking lights, such as tungsten incandescent bulbs, can also provide some measure of UV radiation.
Being a diurnal lizard, it is important that a diurnal cycle be maintained. Lighting should be controlled by timers to give 12 14 hours light in summer, and 10-12 hours light in winter.
The Preferred Body Temperature (PBT) for Bearded Dragons is 35 deg. C (95 deg. F). Their Preferred OptimumTemperature Range (POTR the range of temperature needed to maintain normal body functions) is 35 deg. C to 39 deg. C (95 deg. F to 102 deg. F). This can be attained by basking and by absorbing heat from flat surfaces. To this end, a basking light should be provided at one end of the enclosure to provide a temperature gradient between 29 deg. C and 40 deg. C (84 deg. F to 104 deg. F). Heat mats can be placed under half of the enclosure to assist in achieving this gradient. Heat rocks are not recommended because of the high incidence of thermal injury when using them. Night-time temperatures are usually a few degrees cooler, often attained by just turning the basking light off with a timer.
High humidity is detrimental to the health of Bearded Dragons. Levels in the range of 30% to 40% should be the maximum in an enclosure. Excessive or broad-leafed vegetation can trap moisture and increase humidity, and should therefore be avoided. Cages should be kept clean and dry. In areas of high humidity, it may be necessary to offer water only occasionally and for short periods.
Ventilation is essential to maintain health, but should not be such that difficulties are experienced in maintaining temperatures. Vents should be provided, but care needs to be taken to prevent rostral abrasions on the lizard. If necessary, the roof of an enclosure can be constructed of wire or mesh to allow adequate ventilation.
In an enclosed area the build up of pathogens can occur rapidly. Good hygiene is essential to prevent this. Faeces and uneaten food should be removed daily, and substrate changed every 1-2 weeks. Indoor enclosures should be regularly cleaned and disinfected.
Juvenile Bearded Dragons are predominantly insectivorous, and should be offered small crickets 2-3 times daily. They should also be offered finely chopped vegetables and fruit. These foods can be lightly dusted with calcium powder every second day.
Dragons become predominantly herbivorous as they reach maturity, and should be fed a diet of dark green leafy vegetables (Romaine lettuce, collard greens, endive, spinach, parsley, bok choy, broccoli), carrots, squash, beans and peas. This ‘salad’ should be offered every 1-2 days. Insects can be fed 2-3 times weekly, and a calcium supplement should be added once weekly.
Commercial diets are also available, but should not make up more than 50% of the diet. When these are fed, vitamin-mineral supplements should be reduced or discontinued.
Fireflies (Photinus spp), Monarch (Donaus plexippus) and Queen (D. gillipus) butterflies, and lygaeid bugs (Oncelptus fasciatus) have been reported as toxic to Bearded Dragons, and should be avoided.
Brumation in winter is still recommended for Bearded Dragons in captivity, with some authors suggesting that it may be necessary as a reproductive ‘stimulant’ in early spring. Decreasing the temperature under the basking light to 24 deg. C to 27 deg. C (75 deg. F to 80 deg. F) and the night time temperature to 16 deg. C (60 deg. F) for 4-6 weeks can replicate the natural environment.
As the ambient temperature drops, appetite and activity similarly decrease. Frequency and volume of feeding should be reduced during this period. Soaking the Dragon in lukewarm water 20 minutes every 1-2 weeks can help to prevent dehydration. Shelter (hollow logs, artificial caves, etc) should be provided.
As spring approaches the heat and light available to the lizard should be slowly increased over a few weeks. Once normal activity levels have resumed, normal feeding regimes can be reintroduced.
Bearded Dragons achieve sexual maturity between six and fifteen months; body size and growth rates are more important than age. Most Dragons are ready to breed when they reach 30cm (12″) in length. Males produce sperm all year except for a period of brief regression in late summer. Females, on the other hand, only produce eggs in spring and early summer.
Courtship behavior begins in early spring, as day temperatures increase and the lizards become more active. The male initiates courtship. He approaches and circles the female, waving his arm, changing colour, extending his gular fold, bobbing his head and lashing his tail. Once she signifies acceptance by arm waving and head bobbing, the male grasps the female across back of neck & shoulders in fact, he may even carry her around in this fashion. They then align their cloacas and the male inserts one of his two hemi-penes. The female signals the male to release by raising her head to a near-vertical position.
Short-term sperm storage can occur; related to male competition. The precise length of time is uncertain, although it does not extend between breeding seasons.
Egg laying occurs 2-3 weeks after mating. Prior to oviposition the female becomes quite enlarged in the abdomen, and spends more time basking. She may dig “test holes” prior to laying, but finally digs a shallow burrow, backs into it and lays her eggs, and then covers them loosely with dirt. She may return and defend her nest site for a few hours after laying, but finally abandons the nest site.
Females are generally receptive to males immediately after oviposition.
Each female usually produce 2-3 clutches per season, each of 14-26 eggs (up to 35 eggs have been recorded). Up to 7 clutches have been recorded in captivity. Clutch size varies according to species and age. Clutches may overlap, ie. the female may start to lay the next clutch before the first has hatched. This ability to lay multiple clutches is made possible by the presence of two germinal beds in each ovary (unlike many other lizard species). Each ovary contributes follicles to each clutch, and vitellogenesis begins in the second germinal bed even before the first clutch is laid.
Bearded dragon eggs are incubated for 50 – 70 days at 29 deg. C (84 deg. F), and for longer periods at cooler temperatures. The eggs, 23mm (1″) long at oviposition, enlarge slightly during incubation, and hatch over 2-3 days. The hatchling dragons measure 9cm (4″) at hatch and are independent from the very start.
Care of juveniles
Hatchling Bearded Dragons are miniature replicas of their parents, measuring 9-10cm (4″) in length and weighing only 2-3 grams. They are independent and begin feeding by themselves within a few days. They can be housed individually or in small groups of similar sizes. Juveniles that are not keeping pace with the growth rates of their siblings should be removed to a less competitive environment.
Cages should be kept simple, with minimal furnishings that can conceal food items. Heating and lighting should be similar to adults. If possible, juveniles older than 8 weeks should be housed outdoors to gain maximum exposure to sunlight. If this is not feasible, juveniles should be exposed to unfiltered sunlight for 30-60 minutes every 1-2 days.
Juveniles should not be encouraged to brumate in their first winter.
Ecdysis, the periodic shedding of the keratinised layer of skin, occurs in Dragons in a piecemeal fashion i.e. sections of skin peel away in variable sized sections over a few days. The frequency of this event is determined by species, age, growth rate, ambient temperature and food availability. During spring and summer, when they are active and perhaps growing rapidly, dragons shed more frequently perhaps as often as monthly. During this time abrasive surfaces, such as rocks and branches, should be provided for the dragon to rub against to assist in removing shed skin.