Habitat and Housing Size
What would be the smallest sized cage for an adult blue-tongue skink? Certainly 16″ by 24″ would be the absolute minimum– with a height of 12″ or so (and a screen top to prevent escape); this cramped space is more appropriate for a skink three to nine months old.
A cage 12″ by 16″ would be fine for a baby up to six months or so; then 16″ by 24″ from six months to a year. Ideally, an enclosure for an adult should be 24″ by 30″ — or even better, 24″ by 36″ or ideally 24″ by 48″. Outdoor enclosures can be even larger, perhaps in the range of 48″ to 62″.
Front opening cages that can be stacked are an excellent option for many snakes and lizards, including blue-tongue skinks. Better hide boxes and a real basking platform would improve this condo for BTs.
Professional breeders often use multiple stacking units such as these, and similar units are available from many pet supply stores.
The trusty old glass terrarium serves beautifully for a blue-tongue skink, too.
Here are basic instructions for setting up a terrarium for people needing help.
Reptifiles analyses the pros and cons of various types of reptile enclosures. Cages with finely screened sides work well for chameleons, but are not adequate for blue-tongue skinks, which can rub their noses or even tear through light screen.
Sliding plastic tubs, which are ubiquitous with snake breeders, are not ideal for blue-tongue skinks unless they are relatively large, and provide good ventilation and overhead lighting. On the Reptifiles link there is a setup showing tub enclosures specifically for blue-tongues.
Tiliqua scincoides is not a social species. They are territorial and prefer to keep to themselves, except for brief encounters during breeding season. In captivity, you should house each animal by itself. There are keepers who violate this rule, and sometimes the skinks, especially females, establish a temporary modus vivendi without mayhem. However, this arrangement can result in intimidation, fighting, serious injuries, and even death for some of the animals.
During breeding season males are hyper aggressive. Gravid females can also become hostile, including toward human fingers poking around their homes. After birth, females will defend young from perceived threats until they can safely disperse.
You can keep siblings together in a sizable cage — 16″ by 24″ — from birth until they are two or three weeks old. Multiple hide boxes with a substrate of paper towels is a good option for housing babies together. The papers towels, changed often, maintain hygienic conditions, and prevents the babies from ingesting substrate.
A mixture of human baby food and cat food fed daily in shallow dishes is a good starter food for the first couple of weeks. You should add a calcium supplement with D3 to this soft paste. Fresh water should always be available in shallow bowls — jar lids work well.
Once the young blue-tongues start consuming live food, it is prudent to separate them. As they become conditioned to lunge at live crickets and other insects, the tails and feet of cage-mates suddenly look quite tasty. Also, smaller babies are often intimidated by their more robust siblings, which can hamper their development.
Some species of Tiliqua such as T. multifasciata, T. nigrolutea, and T. rugosa are more amenable to housing in groups, but these are usually only kept in advanced collections (because of the cost and lack of availability) — outside of Australia.
Lighting and Heating
As ectotherms, reptiles use thermoregulation to control their body temperature, which naturally includes all members of the genus Tiliqua.
Adequate caging for blue-tongue skinks, therefore, must include a warm side and a cool side. The only time this would be unnecessary would be during winter brumation (described elsewhere).
All cage heating and lighting should be concentrated at one end of the cage, leaving the other end relatively cool. If the skink needs to warm itself, it can move to the heated end; if it needs to lower body temperature, it will move to the cool side. It’s important that hide areas are offered in various spots along the temperature gradient as blue-tongues will spend the majority of their time in hides.
On the cool side, blue-tongue skink enclosures should have temperatures in the range of 72°- 80°F (23°-27° C.) and the cool side can drop to the low 60°s F. at night. The warm end of the enclosure should have a basking area of 90°-100°F. Heating can be provided by under tank heating, an incandescent basking light (or ceramic heat emitter), or a combination.
Some care sheets recommend hot end temperatures as high as 110°F but this seems too high; these are not desert iguanas (Dipsosaurus dorsalis) that bask in roasting desert temperatures. If the skink can easily retreat to cooler temperatures (70°-80°F), then this isn’t threatening. In summer months, however, the entire cage could overheat and kill the trapped skink.
Overhead lamps mimic natural conditions where skinks bask in sunlight. All heating and lighting devices should be placed on the warm end of the enclosure. If there is an under tank heater, then overhead heating devices can be turned off at night. In order to create a normal diurnal cycle, daylight bulbs should be left on for a maximum of 12 hours.
If you use basking/spot lights in their cages, a moderately raised platform is helpful. A brick, flat rock, or small log permits the skink to situate itself for maximum light and heat exposure. Heat strips placed along the bottom or at the back wall of the cage are an excellent way to heat a cage. These must be outside the cage and limited in intensity so that the skink can move away from them to a cooler area as needed. Heat strips are available in narrow and wide sizes, and a rheostat should be used to control the temperature. The area heated should be warm to the touch (around 100 F./38 C.) — not hot.
Do NOT use electric heat rocks! Heat rocks have reportedly blistered/burnt the skin of reptiles such as blue-tongues. Plus an electrical device inside the tank, where it could get wet and short out, electrocute your lizard, start a fire, etc. is a safety risk.
It is an excellent idea to offer UVB lighting in BT’s enclosures if possible. Alternatively, if you have access to safe outdoor caging, the skinks can be placed in natural sunlight during the warmer months of the year. However, this is risky if done without careful planning.
The caging should be escape proof, and the skink must be protected from menacing animals such as predatory birds, dogs, cats, raccoons, etc. with a sturdy screen top. (Probably a bad idea to leave BTs outside at night where they could be attacked by raccoons or other nocturnal marauders.)
Also, the skink must have an insulated hide to escape overheating. WARNING! If you place your blue-tongue in a glass aquarium in the sun, it can easily succumb to overheating and death. Ideal temperatures for outdoor basking on sunny days would be in the range of 60 F° to low 80s F°. Once the ambient temperature reaches the high 80s F°, the skink is safer indoors. (I have never seen wild blue-tongue skinks active in ambient temperatures above 90 F° [33 C°] in Australia. Although it must happen on occasion, it is uncommon for them to risk exposure at these temperatures.)
There are conflicting opinions about the BT’s need for full-spectrum lighting. There are documented cases of blue-tongues being raised without any exposure to full-spectrum lighting. (I’ve successfully raised and bred Northern BTs without such lighting.) Nonetheless, UVB lighting is still generally recommended for keeping BTs in an indoor enclosure; the lights can be put on a timer for 8-12 hours a day.
Substrate and Cage Accessories
Generally, I use paper towels with baby blue-tongues and then graduate to fir bark or aspen. I’ve also used newspapers but it’s ugly, poorly absorbent, and there are concerns with the inks. Recently, I decided to give shredded coconut husk a try and I’ve been very pleased with it. It costs more than aspen but it holds moisture much better and it is far less likely to get into the food dish. I’ve tried three different brands so far and they all seem similar. I would stick with the larger chips — at least for blue-tongue skinks. It is now my number one substrate recommendation for blue-tongue skinks, although I will continue to use aspen and some cypress mulch for my colony because of their lower costs. It is definitely worth trying the coconut husk to see if your skink approves. I notice many blue-tongues — especially the babies — love to bury themselves in the coconut husk chips, and it doesn’t seem to get in their mouth and eyes the way aspen sometimes does.
“Aspen, recycled paper substrates, fir bark, cypress mulch (not kept moist) and artificial turf (not preferred) can all be used. Whichever substrate is used, be sure the skink does not ingest it. Ingesting substrate can be deterred by using a feeding dish. Blue tongues spend their time on the ground so keep the substrate clean and maintained. NOTE: cedar chips, clay cat litter, orchid bark and walnut shells should never be used. These substrates may lead to toxicity, impaction or respiratory concerns.”
Keeping blue-tongues on sand is not recommended — with the possible exception of species such as Tiliqua multifasciata, which live in sandy areas of Australia. Sand can easily be ingested, causing impaction, and it does not absorb spilled food, feces, etc. very well.
Avoid the use of any type of cedar products as the aromatic oils can harm or kill many reptiles. Pine shavings should also be avoided for BT skinks, although many snake keepers have kept their snakes on pine for years without any notable problems. However, some suspect that oils in pine may also have toxic effects.
The substrate should be kept dry. You can provide a plastic hide box with damp sphagnum moss inside to provide humidity for shedding, but the tank should not be saturated. Wet substrate, especially with soiled food and feces, is an ideal medium for harmful bacteria.
Some keepers advocate for deep fluffy layers of substrate as BTs like to burrow in it. But this can causes problems as it gets in the water bowl and food, and can irritate the eyes and nostrils of your BT. It also makes it more difficult to clean the tank, makes it impossible for skinks to find insects, and makes it a challenge for you to find your skink! Good hiding spots and moderate use of substrate is probably a better solution.
Blue-tongue skinks need fresh drinking water. It’s important to offer a sizable water bowl as the skink will often immerse itself in it to help with shedding. BTs often use their water bowl as a toilet so it should be cleaned regularly.
Many keepers recommend rough rocks or bricks in the cage to help file down toe claws. Blue-tongue skinks are not agile climbers so branches are unnecessary. However, BTs will clamber out of enclosures if they can — don’t underestimate their determination. A tank should have a sturdy screen top unless the tops of the walls are completely out of reach.
Proper housing accessories could include cork bark, gnarled mopani wood, hollow logs, large rocks, and plastic hide boxes or shelters. Some keepers use PVC pipe cut into short sections as hides; obviously, the diameter should allow easy egress. BTs enjoy wandering so avoid unnecessary clutter unless it’s functional.
As mentioned earlier, BTs are not active in blistering heat in the wild. As diurnal lizards, they will often bask if temperatures are low to moderate. I’ve observed both T. nigrolutea (blotched) and Eastern blue-tongues basking in the morning sun when ambient temperatures were around 60° to 75° F.
These skinks live at higher latitudes, with generally cooler weather, than Northern blue-tongues. Darwin NT, where Northern BTs thrive, is only 1200 kilometers south of the equator; the Melbourne area, home to Eastern and Blotched blue-tongues, is about 4200 kilometers from the equator. This is an impressive range of habitats and climate zones without even including the BTs of Indonesia and New Guinea.
Blue-tongue skinks are primarily diurnal but some species will move around at night during warm evenings. The Centralian blue-tongue skink, T. multifasciata, often spotted basking on asphalt roads on sunny cool mornings, shifts to crepuscular or even nocturnal activity during the summer heat. Near Darwin, I have observed Northern blue-tongues occasionally crossing roads at night, especially during monsoon rains.
Diet for Blue Tongue Skinks
Blue-tongue skinks are opportunistic omnivores: they are highly flexible in their dietary intake, willing to ingest anything from beetles and grasshoppers to rotten fruit and road kill. In their ecological niches they are generalists, with an emphasis on arthropods but with an open-mindedness to gobble up just about anything available.
In captivity, BTs will eat an amazing range of foods. Many care sheets suggest a ratio that should consist of 50% fresh vegetables, 40% protein foods, and 10% fresh fruit. I am not sure of the origin of this golden ratio but it seems to be widely copied.
However, from my experience I would suggest something closer to 50% to 70% protein foods (especially insects and molluscs), 15% to 25% vegetables and seeds, and 15% to 20% fruits. For one thing, this is closer to their natural diets — except for the shingleback skink, whose diet should be around 80% plants, flowers, vegetables, and seeds.
Regarding the 70% protein foods, this should not be exclusively portions of canned dog and cat food. The protein levels are actually low in these foods, and the calcium/phosphorous ratios are not appropriate for reptiles. Some people get good results using these commercial mammal foods, but BTs often develop metabolic bone disease and serious health problems on monotonous diets lacking healthy variety. A lack of UVB and/or D3 supplement contributes to the disease.
My Northern BTs refuse to eat plain old greens and vegetables. They react to collard greens with the same enthusiasm as a typical 10-year old, which is to say none at all. The best trick is using a food processor to chop/grind greens and vegetables, and then add them to a more palatable food such as a premium dog/cat food or minced meats. Adding some diced fruit such as berries, apples, or grapes can help the greens go down.
Neonatal blue-tongue skinks should be fed daily as much as they will eat. After a month or so, feeding every other day is sufficient. Adult skinks do well on two or three feedings a week, and it is not unusual for them to skip meals for a week or so.
Protein sources include:
- Feeder insects such as crickets, roaches, & superworms. Superworm larva and beetles, which can be produced by isolating the worms, are tasty, too. Some BTs eat earthworms. Insects can be dusted or gut-loaded with extra nutrients.
- Molluscs — BTs go crazy for snails. If you feed snails collected outdoors be absolutely certain they have not consumed poisonous snail/slug bait as this can kill your skink. The brown garden snail (Cornu aspersum), common in U.S. gardens, was actually introduced from Europe in the 19th century for escargot. You can also buy canned snails for your BTs.
- Fresh killed/thawed feeder rodents. You can feed pinkies to young BTs, and small adult mice to large BTs. Dipping them in raw egg and feeding them off tongs, usually motivates a hungry skink.
- Moist super premium dog or cat food (i.e. turkey, venison, or lamb based). Avoid fillers, grains, and artificial additives. Mix these with grated vegetables & greens to increase the quality of the food. I sometimes mix in a raw egg and diced fruit. Mixed thoroughly, you get a viscous salad that can be served to BTs in a shallow bowl. By placing paper or a thin tray under the bowl, you keep substrate out of the food and make it easier to clean up.
- Minced/ground meats: raw hamburger (lean); cooked turkey or chicken; ground chicken necks; cooked chicken liver or heart.
- Eggs: raw, scrambled or boiled. Blue-tongues will eat the eggs or chicks of ground nesting birds when they find them.
- Optional commercial foods: ZuPreem’s Monkey Biscuits (soaked); ZooMed’s canned grasshoppers; canned omnivore and lizard chows; Harrison’s Bird Diets High Potency Coarse Pellets.
- Vegetable Options: Peas, collard greens, turnip greens, mustard greens, zucchini, all kinds of squash, such as spaghetti, scallop, butternut, acorn; canned organic pumpkin; carrots, bell peppers, dandelion leaves and flowers, Hibiscus flowers; soaked or sprouted beans, lentils, and other seeds. Kale and spinach contain high amounts of oxalates, which can bind to calcium. However, used occasionally these are fine.
- Fruit Options Include: Strawberries, peaches, grapes, figs, mango, raspberries, papaya, cantaloupe, blueberries and apples. BTs love bananas but feed only in small amounts
- Foods to avoid: Onions, citrus, avocado, eggplant, rhubarb, high-sodium canned meats, and high sodium dog/cat foods and treats. No Spam, beer, kit kats, chocolate pie, or chewing tobacco.
Here we have a blue-tongue skink sleeping in the sun in a Sydney garden…with a wandering snail using it as a speed ramp. Posted on a gardening blog called ‘Happy Earth’.
Additional BT skink suggested food lists:
An Astounding BT skink recipe from April at Arctic Exotics (I’ve yet to make a batch but….)
Additional Care Sheets for Blue-Tongue Skinks: