Providing proper heating and lighting is essential to keeping caged bearded dragons healthy. Their activity and metabolic processes depend on proper light and heat gradients. Without them, your dragons cannot survive.
Providing adequate heat is critical to the welfare of bearded dragons. The primary source of heat should be a white (not red) incandescent bulb or spotlight in a reflector-type fixture capable of handling the wattage and heat output. A fixture with a ceramic base and no electrical switch in the base typically last longer for this kind of use. Look for a fixture with a switch on the cord, or plug the fixture into a surge suppressor unit and use that switch to turn it on and off. The fixture should be placed on or above the screen top over basking sites such as flat rock or wood. The temperature measured at the site should be 90–100°F, and the bulb wattage should be adjusted to provide the proper temperature. An alternative is to use a higher wattage bulb and wire or plug the fixture into a light dimmer. This allows you to adjust the heat output.
When raising baby bearded dragons, many hobbyists choose to include a hot rock type of heater as a secondary heat source.
During the warmest time of the day when temperatures can reach 100°F, these bearded dragons choose to rest in the shaded portions of their green-house enclosure.
Several bearded dragon specialists recommend combining a hot rock with an overhead spotlight. The temperature at the basking site should measure 90–100°F. Placing rock and other heat absorbing landscape materials under a spotlight can help heat up a basking site more effectively.
As a secondary heat source, a “hot rock” type heater works well with this species and should be placed away from the spotlight heat source unless intentionally combined with a lower wattage incandescent bulb.
Beware of Fire Hazards!
Spotlights generate a great deal of heat and can start a fire if placed too close to combustible materials, such as curtains. We cannot emphasize enough the importance of placing spotlight fixtures securely above the metal screen top of an enclosure and away from curtains and other flammable materials. If you have small children, cats, or other uncaged pets who are likely to topple fixtures or trip on electrical cords, limit access to the room where you keep your bearded dragons. Another cause of fire is placing spotlights on rugs or furniture while doing maintenance. This is especially dangerous when you have a light connected to a timer. Even though the light may be off when you move the fixture, the spotlight will burn whatever lies beneath it when the timer goes on the next day.
Finally, and most important, put a functioning smoke alarm in any room where spotlights or other kinds of heating units are used for reptiles.
Note the central raised keel of the scales, which increases surface area and helps regulate body temperature on this female Sandfire bearded dragon.
A key to successfully keeping reptiles is understanding the role of heat. Reptiles are ectotherms, which means that they depend on environmental temperatures to achieve and maintain optimal body temperatures. However, reptiles are not passive in their relationship with environmental temperatures. They thermoregulate by various behaviors including selection among thermal zones.
After a cool night in the desert, a lizard may crawl out into sunlight at midmorning, flatten its body, and adopt an overall darker coloration to increase heat absorption so that it can quickly warm up to an effective operating temperature. This allows it to be alert and fast. Once an optimal temperature is reached, the lizard may hunt insects, perform displays for other lizards, and be wary of potential predators. However, as the midday sun causes air and surface temperatures to rise even higher, the lizard may begin to overheat and will move out of the sun to rest in shade or a shelter until the temperature cools down.
One of the interesting features of reptiles is that that they heat up quickly and cool down relatively slowly. In fact, one of the studies showing this was done with the eastern bearded dragon (Bartholomew and Tucker, 1963). Individuals with a 68° F body temperature placed in a 103° F chamber heated to 101° F in about thirty-eight minutes but under reverse conditions required more than fifty minutes to cool from 103° F to 69° F. Thus, a heated reptile can store heat and maintain a relatively high body temperature for an extended period of time.
Killing Them Softly in Small Tanks
FAQ:I bought a bearded dragon three months ago and I set it up in the 10-gallon tank the pet store sold me along with a spotlight and hot rock. It did well until recently, when it started gaping and stopped feeding. It died two days ago. What happened?
This is a common scenario when baby bearded dragons are raised in tanks that are too small. Initially, because they are small, they can move away from the heat sources. But as they grow larger, their increased body size makes it impossible to escape the heat. Bearded dragons don’t just grow in length, they also grow in height and width, exposing them to more heat than babies. The typical sequence of events is that they first start panting in a desperate attempt to cool off, then they stop eating because survival is becoming their primary concern. Finally, they overheat and die. Because of their rapid growth rate, a 10-gallon tank is not an adequate size for rearing bearded dragons past three to four weeks of age. Next time start with a larger tank.
FAQ:I recently bought a baby bearded dragon along with a 10-gallon tank and a 100-watt spotlight the pet store recommended. The baby fared well for a couple of weeks and died. What happened?
This is another common scenario with baby bearded dragons. In a 10-gallon tank, a 100-watt spotlight can generate a temperature over 100°F within most of the dragon’s available space. Even if it can initially get away from the heat, before long, as it grows larger, the dragon will be stuck in the hot zone and cook. Bulbs of 60–75 watts will be adequate for smaller tanks, although a 10-gallon tank is not a proper size for rearing baby bearded dragons. Remember what we emphasized earlier: Bearded dragons need a sizeable cool area to escape excessive heat.
We hope this information will emphasize the importance of providing a basking site of around 95°F to allow bearded dragons to thermoregulate. You also will have to provide a cooler, unheated section that they can access once an optimal temperature is achieved. Let bearded dragons choose what to them “feels right.” Improper heat gradients are one of the most common causes of illness in bearded dragons and other reptiles.
Optimal temperatures allow efficient metabolism and immune system activity in reptiles. If kept too cool, the metabolic processes of reptiles will occur at a slower rate and the immune system will become depressed. Cool temperatures reduce digestion rate, which can lead to gastrointestinal problems such as decomposition of food in the gut and bloating. The equilibria of bacteria and protozoa in the gut may also be thrown out of balance. Moreover, the rate of clearing uric acid and other compounds through the kidneys is reduced at suboptimal temperatures and the risks of kidney disease increased. Growth rate, which depends on appetite, rapid digestion, and effective metabolism, is directly affected by temperature.
Bearded dragons benefit from good lighting. They are less spirited and less active when kept under low light, as you may have seen in pet stores that use ceramic infrared heaters as primary sources of heat. As you probably know, even the moods of humans are affected by low light exposure. How could one expect any less with a sun-loving animal such as the bearded dragon? In addition to spotlights as heat and light sources, full-spectrum or high-UV-B reptile bulbs should be provided from above in fluorescent fixtures that run the length of the enclosure.
The reasoning behind our recommending bulbs that generate UV-B involves vitamins and minerals. It is hypothesized that basking lizards, such as bearded dragons, manufacture vitamin D3 when exposed to UV-B radiation from sunlight. Because lizards need vitamin D3 to effectively absorb calcium, lack of this vitamin in the diet or lack of exposure to a UV-B source can lead to calcium deficiency. This becomes very noticeable in baby lizards, which require large amounts of calcium to build rapidly growing skeletons. To prevent this, be sure to provide appropriate amounts of calcium and vitamin D3 in the diet, along with exposure to UV-B radiation, either via sunlight or special bulbs.
Our observations suggest that bearded dragons eat more, grow faster, and are healthier and more active when provided with sunlight or full-spectrum/reptile UV-B bulbs. In one experiment we had specimens fed ad libitum grow 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 growth rate was significantly greater compared to specimens raised under conditions where any of three factors, light-generated heat, UV-B-generating light, and food availability were limited. There are now mercury vapor bulbs sold in the reptile trade that fit incandescent fixtures, produce good levels of UV-B, and emit some heat. They are very effective as a UV source but should not be used as the only heat source because many lizards choose to limit their exposure to high-UV sources. In short, they’re great at one end of a large tank with a standard spotlight at the opposite end.
You can make a wooden indoor display with concrete blocks to provide basking sites, nail wearing sites, and a shelter. Provide a spotlight and a UV-B-generating fluorescent bulb. Photo by Val Brinkerhoff, courtesy of Dan McCarron.
Darkness and Feeding
FAQ:I have a couple of half-grown bearded dragons in a 4-foot tank with a 75-watt spotlight for heat at one end. The problem is that they don’t seem interested in eating and they sleep all the time. Should I take them to a veterinarian?
Don’t rush to the clinic just yet. This is another common problem with bearded dragons that are not set up correctly. We see it in pet stores all the time. Bearded dragons are diurnal animals that derive psychological benefits from a high light level. A single spot on a large tank means that most of the tank will be too dark. A consequence of low light is poor appetite.
You should have full-spectrum, high-UV-B, reptile fluorescent bulbs running the length of your tank for up to fourteen hours a day. If after a couple of weeks your dragons don’t perk up and show significant improvement in appetite and activity, then you should take them to a qualified reptile veterinarian. Beware, however, of veterinarians inexperienced with bearded dragons. They can sometimes do more harm than good.
Of course, the inexpensive alternative to UV-generating bulbs is to allow bearded dragons regular exposure to sunlight during the warm months.
The easiest way to provide UV-B is to expose lizards to sunlight. The safest way is to expose them to sunlight to use screen-sided cages, which reduce the risks of overheating. A commonly used alternative is to place bearded dragons in large opaque or white plastic storage containers 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 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 or soil is a safe place for these cages. Beware of concrete patios or asphalt surfaces, which build up heat in the sun and can kill your dragons.
Bearded Dragons and UV lighting
FAQ:Is it possible to raise bearded dragons without using a source of UV light such as the special reptile UV-B bulbs?
We have raised all three popular species of dragons to adulthood without exposure to UV-B, using regular supplementation with vitamin/mineral mixes that contained calcium and vitamin D3. However, we feel that raising these lizards without a UV source is a gamble. With the current method of dusting food with powdered vitamin/mineral supplements, we simply don’t know enough about the long-term effectiveness of the formulas and proper dosage. By far, the most common health complaint with baby bearded dragons continues to be signs of calcium deficiency such a hind leg twitching. Exposure to a UV source appears to be the most reliable way to provide these lizards with adequate levels of vitamin D3 to allow absorption of calcium. We also don’t know all the other benefits of exposure to a more balanced lighting that comes closer to natural sunlight, including psychological benefits. If you live in a sunny area, exposing your lizards to UV source should be easy and economical during the warmer months of the year. Two to four hours of sunlight a week is probably enough to meet the needs of bearded dragons.
This green-house is set up to house both frilled dragons (Chlamydosaurus kingii) and eastern bearded dragons (P. barbata). The trees are dracaenas.
Light, Heat, and Coloration
Proper light and heat can help bring out your dragon’s true colors. The bright orange-reds and yellows of certain lines of bearded dragons do not become fully expressed when they are kept indoors. One or more factors related to light conditions (and possibly heat) appear necessary to trigger the hyperxanthic response (an increase in yellow and orange skin pigments). This is comparable to the hypermelanistic response (increase in dark pigment melanin) of human skin to UV radiation from the sun. The bearded dragons we raise outdoors under greenhouse plastic that filters 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.
Under indoor conditions, we have tried UV-generating reptile bulbs (both fluorescent and mercury vapor) and were unable to get Sandfire dragons to fully color up. However, individuals raised indoors under a combination of mercury-vapor UV-B bulbs (they have a higher UV output than fluorescent reptile UV-B bulbs) and incandescent spotlights that raised basking site temperatures between 90° and 100° F did develop significantly brighter coloration than animals raised without this combination of heat, UV, and possibly light intensity. That the coloration is a response to external conditions is illustrated by the following example: A group of Sandfire dragons we had sold were bought back after eighteen months because the owner felt their coloration was not up to par. Because we had initially kept back half the clutch of this particular group, we were able to compare the effects of raising conditions. Our greenhouse-raised animals were a bright orange-red while the ones raised indoors were dull with scattered hints of orange. We placed these dull dragons in our greenhouse under plastic and this group steadily brightened, requiring a full three months to achieve the Sandfire coloration.
A Sandfire bearded dragon raised indoors under optimal conditions including spotlights and high UV-B rep-tile bulbs is remarkably colorful.
Once mature (after one year of age), bearded dragons usually enter a state of brumation, commonly termed shutdown, 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 winter shutdown, dragons must be maintained at cooler temperatures (60–70°F), something easily achieved in most homes by placing the enclosure on the floor of a room during winter months. Basking lights should be reduced to a lower wattage (basking site reduced to 75–80°F) and left on for only eight to ten hours daily. Many owners are alarmed by the drastic change in behavior during this period and believe their dragons may be sick. Winter shutdown, however, is normal for this species. Winter shutdown 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 such as sunken eyes, gaping, or twitching.
Winter Shutdown and False Signs of Disease
FAQ:My bearded dragon had been faring well until last month (November) when it started spending most of its time hidden. It has also refused any food, and I’m worried it may be sick.
We can’t say for sure whether your bearded dragon is actually sick or not. Very likely what you are being faced with is what we call “winter shutdown and the false signs of disease.” Indeed, a common reason first-time dragon owners consult veterinarians is winter shutdown. This is a natural rest period for bearded dragons over a year old, and it appears similar to certain signs of disease. Bearded dragons don’t feed, they are inactive, and they hide most of the time. When these animals are brought to inexperienced veterinarians, unnecessary, costly, and sometimes harmful procedures are recommended.
To assess the health of your bearded dragon at this time consider the following: If this shutdown occurs in the winter, if your dragon is not losing much weight and is maintaining rounded body contours, if it appears relatively alert and wide-eyed when picked up, then it is probably fine and just doing what bearded dragons naturally do at that time of the year. It’s most important for you to keep it at cooler temperatures 66–70° F during this period of time. Only in the case of clear signs of disease, such as rapid weight loss, sunken eyes, gaping, forced exhalation, eyes that don’t fully open and a limp rag doll feel when held, should a dragon be brought to a veterinarian during apparent winter shutdown.
There are two approaches to winter shutdown. In the first, the owner can create a shutdown cycle of cooler temperatures and shorter day length, similar to what happens in the wild. Owners need to reduce, then eliminate food for the dragon about one week before the onset of cooler temperatures. Alternatively, an owner can wait and observe the dragon closely, and then create shutdown conditions as soon as the dragon shows signs of reduction in activity and food intake. The end of winter shutdown is marked by a shift in behaviors following the increase in heat and light that accompanies spring. Return dragons to normal conditions as soon as they start basking and feeding again.
Note: Inexperienced veterinarians may fail to recognize winter shutdown and recommend force-feeding during this period. Don’t do it. Force feeding at this time is harmful to a dragon.