than compact screw-in types.
We also recommend that you locate your dragon in a bright, well-lit room of the house. We have found that when bearded dragons are kept in a very bright environment, they eat better, are brighter in color, and are much more active than without bright light.
Providing UVB is critical to aiding the dragon in generating vitamins and minerals. It is hypothesized that basking lizards, such as bearded dragons, manufacture vitamin D3 when exposed to UVB radiation from sunlight. Because lizards need vitamin D3 to effectively absorb calcium, a lack of this vitamin in the diet or a lack of exposure to a UVB source can lead to calcium deficiency in the dragon. This condition becomes very noticeable in baby lizards, which require large amounts of calcium to build their rapidly growing skeletons.
A calcium deficiency in bearded dragons further results in metabolic bone disease (MBD), a crippling disease that deforms the bones, especially those in the back. To prevent MBD, provide appropriate amounts of calcium and vitamin D3 in your dragon’s diet along with exposure to UVB radiation in the form of sunlight or UVB-generating bulbs or fluorescent-type tubes.
Our observations suggest that bearded dragons do, in fact, eat more, grow faster, and remain healthier and more active when provided with sunlight or full-spectrum/reptile UVB fluorescent tubes. In one experiment, specimens that were fed ad libitum grew from hatchling to 14 inches long in fourteen weeks by combining a spotlight heat source with full-spectrum bulbs placed 6 inches above the experimental group. This group’s growth rate was significantly greater compared to specimens raised under conditions where any of three factors—light-generated heat, UVB-generating light, and food availability—were limited.
Light goes hand-in-hand with heat in providing an optimal bearded dragon environment.
Mercury vapor bulbs sold in the reptile trade fit incandescent fixtures, produce good levels of UVB, and emit heat. They are effective as a UVB source; however, you must ensure that your dragon does not become dehydrated in an enclosure with a mercury vapor bulb. We would never recommend that you use them with juvenile bearded dragons because the results are usually disastrous. There are also bulbs, such as Mega-Ray bulbs, that produce very little to no heat but do provide UVB. If you use this product, make sure to give your dragon a basking lamp for heat and also some sort of visual lighting.
One easy way to provide UVB is to expose lizards to sunlight. The safest way to expose them to sunlight is to use a screen-sided “basking cage,” which reduces the risks of overheating. A commonly used alternative is to place the bearded dragons in a large opaque or white plastic storage container with a screen top. Glass-sided, clear, or bare-floor plastic containers risk overheating and are often lethal to dragons when placed in the sun. Instead, use sand and cover part of the storage container with cardboard for shade. Even with screen-sided enclosures, you should always provide an area of shade so your bearded dragon can get out of the sun. Placement of basking cages is also important: grass and soil are safe, but beware of concrete patios or asphalt surfaces, which build up heat in the sun and can kill your dragon.
Light, Heat, and Coloration
Proper light and heat can help bring out your bearded dragon’s true colors. The bright orange-reds and yellows of certain lines of bearded dragon do not become fully expressed if temperatures are not optimal for that dragon. One or more factors related to light (and possibly heat) appear necessary to trigger the hyperxanthic response, which is an increase in yellow and orange skin pigments. This is comparable to the hypermelanistic response in humans, which is the increase of the dark pigment melanin when human skin is exposed to UV radiation from the sun. Bearded dragons raised outdoors under greenhouse plastic that filters out most of the UV radiation become just as bright as individuals kept in the open, so UV radiation may not necessarily be the triggering factor.
At Fire and Ice Dragons, we found that in indoor conditions, our bearded dragons are brightest under correct basking temperatures, very bright visual light, and Repti-Sun 10.0 fluorescent UVB tubes or Arcadia T-8s.
We also tested various types of tanks: glass tanks, top cages in various colors, wooden enclosures in various stains, all-screen cages, and enclosures with solid sides, tops, and backs. We observed how these situations affected the dragons’ coloration. Bright Super Citrus dragons that were placed in dark-stained or granite-colored enclosures darkened immediately, even with optimal basking temperature and UVB output. In screen cages, brilliant yellow Super Citrus bearded dragons dulled to gray. They were cold, and the screen blocked the visual light from the room.
Conversely, the dragons placed in all-white melamine enclosures with solid tops, sides, and backs with sliding glass doors in front were brightest in color when compared to all of the other caging systems we tested. We can only assume that the highly reflective quality of the white melamine raised the visual light within the entire enclosure. This makes sense, as Australia is a very bright continent!
Lighting helps keep a dragon’s colors rich and vivid.
Brumation (Winter Shutdown)
Once mature (after one year of age), bearded dragons usually enter a state of shutdown, commonly termed “brumation,” in which they remain relatively inactive, hidden in shelters or lying on the ground and eating little, if at all. If raised under indoor conditions, babies hatched out in the summer won’t undergo winter shutdown until the following year (at about eighteen months of age). During brumation, dragons must be maintained at cooler temperatures (60–70 degrees F), something easily achieved in most homes by placing the enclosure on the floor of a room during the winter months. Owners should decrease the wattage of basking lights to reduce the basking site’s temperature to 75–80 degrees F and leave the basking lights on for only eight to ten hours daily. Many owners are alarmed by their dragons’ drastic change in behavior during brumation and worry that their dragons may be sick. A period of brumation, however, is normal for this species. Brumation can last from a few weeks to five months. If bearded dragons are healthy, they will lose little or no weight during this period and will remain in good condition, showing no signs of disease (e.g., sunken eyes, gaping, twitching, wheezing).
There are two approaches that beardie owners can take during brumation. In the first approach, the owner can create a shutdown cycle of cooler temperatures and shorter day length, similar to what happens in the wild. The owner needs to reduce, and then eliminate, the dragon’s food about one week before the onset of cooler temperatures, allowing the dragon to empty any remaining fecal matter in its intestines. Alternatively, in the second approach, an owner can wait, observe the dragon closely, and then create brumation conditions as soon as the dragon shows signs of reduced activity and food intake.
The end of brumation is marked by a shift in behavior following the increase in heat and light that accompanies spring. At this point, the owner should return the dragon to normal conditions as soon as it starts basking and feeding again. Start with easily digestible foods, such as greens, until the dragon’s normal bodily functions return. Soaking daily will help the dragon wake up.
Bright light and heat during the day is balanced by “lights out” overnight.
