DISCLAIMER: Everything shared below relates to the care of two specific subspecies of Blue Tongue Skink (BTS), that being Northerns from Australia (Tiliqua Sconcoides Intermedia) and Irian Jayas from Indonesia (Tiliqua Sp.) Many pieces of my care advice are broad and can be applied to all species of Tiliqua, but other pieces of advise may not be applicable and potentially dangerous to the well being of a different Blue Tongue Skink.
I do not claim to be a zoologist, nor obtained a formal education in animal husbandry. Every piece of information shared here I stand by, but that does not mean I know everything. Someone else may care for their skink differently than I but it does not mean either of us are wrong. Fortunately, these lizards are quite hardy and have a wide spectrum on what it takes to thrive. I may update this section periodically as I learn more about their needs in captivity.
This is a collection of useful information I have come by from Internet research, various Blue Tongue Skink (BTS) books, tips from other breeders, and evidence-based, trial & error practices from being a pet owner since 2000. What’s shared below are a combination of unsourced facts as well as personal opinions on various aspects of care. I welcome you to do additional external research if you do not find this information sufficient enough.
WHAT IS A BLUE TONGUE SKINK AND ARE THEY RIGHT FOR ME ANYWAY?
The BTS is the largest lizard in the Scincidae family. Adults commonly grow to reach a range of 1 lbs – 3.5 lbs and 16″ – 28″ from snout to tip of tail; roughly the size of your forearm (wrist to elbow). Overall they are a hardy medium-sized lizard. Native to both Australia and Indonesia (and Papua New Guinea), they do quite well in captivity in America. They are slow, curious creatures, that have been in the pet trade (as far as I’m aware) since the 1950’s. They like to burrow and often mis-identify your fingers for food – they’ll eat almost anything. Their nicknames include: Smooth Noodles, Sausages, Snakes With Legs, and Pinecones – if you have a Shingleback (Tiliqua Rugosa). They will bond with their hooman, generally accept boops on the snoot, but not afraid to let you know when to leave them alone. They tend to sneeze a few times a day, and show gratitude for changing their water bowl by defecting in it. They get sucked into TV shows but are easily distracted by a dark crevice to burrow in – like the corner section of your couch. Even though they may do some things that have you questioning how they managed to outlive the Dodo, they are quite smart and can use that intelligence to be afraid of you if they are not handled regularly. They have long lives, need a fair amount of space, and especially with the Indonesian species – humidity is key. Additional literature about Blue Tongues care in captivity can be found here, here, here, and here – though I cannot vouch for any care section being up to date other than my own. If anything mentioned above or below seem unlikely to jive with your lifestyle, please take all accounts into consideration before adopting one of these majestic creatures into your home.
Babies (less than two sheds old) are fine in a shoe box size storage container. Multiples may be housed in a 20-gallon tank. If they are fed live food, it is encouraged they be fed individually because once they get an idea to attack moving food, they may take a bite out of their brother or sister. By their second shed they get territorial and need to be separated and housed individually for the rest of their lives.
They are considered babies for the first 6 months of life and a juvenile until they reach adult size. Each grows at their own rate and may be full size at 8 months… or 30 months – yes.
Every once in a while you get a pair or a group that genuinely enjoy being together as adults, but this is the exception and not the norm. I have also seen BTS housed with bearded dragons and frilled lizards but do not recommend this housing set up to a beginner. They are solitary creatures in the wild and it is best to keep them that way.
Adults need 48” x 17” minimum floor space. That is a 40 gallon long. A standard 75 gallon tank works just as well and seems pretty easy to find on Craigslist, though a front facing door is best.
Some people who use rack systems keep theirs in 36” x 18” tubs. I personally disagree with this housing size. These animals enjoy exploring their environment. The more space they are given, the more they will utilize the space. Seeing as how they get to be 18” long on the small end and 28” long on the large end, when you add in water dishes and other furniture taking up residence, a 36” x 18” seems cruelly cramped.
The closer you can provide to 1000 sq. in. floor space or more, the better.
Height is less of an issue. Blue Tongue Skinks (BTS) are ground dwellers and burrowers. If a tank is too tall, they tend to engage in a behavior called “wall riding”. The more they do this, the larger of a dip their spine gets which may create health problems later down the line. With that said, they love to climb over stuff and explore.
I recommend materials that are dishwasher safe or inexpensive enough to be readily replaced. If they defecate on their furniture, it needs to be cleaned up and sanitized or risk getting the animal sick, or attracting bugs and mites. Natural wood and cork items are notorious for this and difficult to sanitize properly. Purchasing expensive reptile, outdoor themed items are nice, but also not a necessity. A plastic PVC tube suites them well, but remember these reptiles may prefer to curl up vs rest totally extended – more options the better. They require at least one hiding place to feel safe. I recommend adding in fake green vines and plants that allow them to hide. It helps them believe they are in a more natural environment.
A large or extra large water bowl is most appropriate for an adult. Ceramic water dishes, pyrex glass or even shallow Tupperware suites them fine as well. While they may not soak or submerge, like a water dragon, they may run their entire body through the water to get clean. The water bowl should not be deep enough where they can drown, as these creatures are poor swimmers. When shopping for a water bowl, consider weight. Skinks are strong and will try to burrow underneath the water dish. If your bowl is too light weight, this will happen:
I utilize two food dishes, both kept on the cool side. One has dry dog food they can pick at as they please, and the other contains a wet salad mix that gets changed out more frequently. I have also seen people use a third food dish that just has Calcium + D3 powder the skink can dip into when ever they need. Their food bowls should be relatively shallow and can be as small as a ceramic mealworm feeder.
Adding a brick or rough slate to the habitat will be good for their nail maintenance and helps get skin off during shedding. The bricks should be dispersed throughout the tank but slate can be added under the heat light for a nice basking spot. If slate is added under the basking spot, be weary of just how hot that basking spot gets. A digital laser thermometer is great to have on hand. Don’t need to go crazy expensive.
SUBSTRAITS AND HUMIDITY
To start off, going bioactive has been proven very successful with most blue tongue species, especially the higher-humidity Indo species. But I have never ventured down that path so I don’t want to comment or advise how to do it properly. The Bio Dude is who I would refer you to for bioactive questions. What I do is a little different…
I prefer all lose and natural substrates. Some of the options that can be used successfully include: Cypress Mulch, Large Aspen Bedding, Reptile Bark, Organic Top Soil, Play Sand, Sphagnum Peat Moss, Coco Husk, and Reptile Floral Moss. Zoo Med Laboratories is the number one brand I buy. Zoo Med Repti Bark is used for the cool and dry half, while, Zoo Med Forest Floor Cypress Mulch, and Zoo Med Coco Earth are all mixed together for the hot and humid half. Zilla’s Jungle Mix (Peat Moss and Sphagnum Moss) is also used considerably, and now, a cup of play sand is also added, resulting in tremendous benefits for retaining humidity in the 50+% range. The more natural wood-type substrates are best. I put in enough for them to burrow and submerge their entire body. You will often find tunnels they have excavated for themselves. I will also add another type of green, fluffy moss to the surface of an area that gets moisture to create a natural humid hide while adding lush color to the exhibit. They especially like these areas during shedding. I tend to replace my substrate every 6 months or even once a year if all goes well, but you may need to do so every other month depending on what you choose and how clean you like it. To keep the substrate fresh, till all the substrate every week or two, and every time to the areas you add moisture to as well. This will keep mold away and fluffyness up.
Now because this is a natural substate in a contained ecosystem, and there’s lots of stuff going on, bugs may just appear over time. They can be harmless, they usually are, like fruit flies, or beneficial like springtails, but they can be catastrophic like mites. General rule is if there’s bugs on your lizard, there’s a problem. If the bugs are just there in the tank, they’re probably helping. Isopods and springtails eat moisture and mold. A mite may burrow under your skinks scales and take over. If it really bothers you, use that as a gauge when to change the substrate.
A more economical option is going to a hardware and garden store like Lowe’s and buying organic, chemical and pesticide free products. You may need to look at each label and each brand, and do additional research on the company’s website, but I can verify No Float Cypress Blend Mulch meets the criteria. The risk with any product from a hardware store are the risks of introducing molds, bacteria, and bugs. To minimize and reduce risk, freeze the substrate for 2 weeks prior to use to kill any bugs and mold. You can also bake it on a flat baking sheet in your oven at 225F for 45 minutes. The baking method I have not tested myself so please monitor when placing wood chips in the heated oven.
The reason I don’t just use cypress mulch alone on the hot and humid side has to do with where I live, how I keep my home, and the lights I use. Everything is geared for evaporation. If I just used cypress and a large water bowl, my tanks would likely have 25-35% humidity. Any other home and set up might garner slightly different results even doing everything the same so it is important to monitor readings accurately in the tank, and if you are a newbie, have the tank running without the lizard for a few weeks to make sure everything will be perfect for them prior to arrival. But at 25-35%, that dry of an environment will wreak havoc on their skin in a few days, and permanent lung problems in a few years. So to maintain the 50% and higher humidity levels, I add 20% Zilla Jungle Mix and 20% of Coconut Husk on the hot side, and mix it all up. I now add a cup of play sand too to boost and hold humidity levels that Cypress Mulch cannot reach alone. The combo has worked out real well. The ratios mentioned above are all approximates and the Indo will always get more of everything that is not cypress.
There is this rumor floating around, ingestion of the coconut husk can be toxic. I think that comes from blue tongues not eating coconut and substrate made from walnut shells known to be toxic to Blue Tongues. With that said, I still use it. As a precaution, I only add it to the hot side and keep all food on the cool side. Coco Husk t is the predominantly used fiber with all Indo species.
A tutorial video on adding water for humidity and tilling the substrate can be seen here:
For humidity, I’ll add a few cups of water every 2-5 days and till the substrate on the hot side when water is added. See video above. This process keeps humidity levels up and mold levels down. I will also till the cool side, which is 100% ZooMed ReptiBark, just in case moisture had been sitting or feces went undiscovered, to keep the tank clean at all times. The water used doesn’t need to be filtered. Just regular tap water is fine. And room temperature is best. Too hot grows bacteria, and too cold doesn’t generate the humidity you seek. Be cautious how much water you are adding as well. You want the substrate damp but not soupy-wet. Too wet will lead to skin infections as well. They manifest under the chin and under the belly or hands and look like tiny cigarette burns. Little diluted Betadine and Neosporon, plus drying out the tank resolves the issue in a few days.
When you decide to do a full substrate replacement, a full disinfection and sanitization should be done to the habitat too.
Indoor/outdoor carpet is alright. They still need places to hide to feel safe and I find the carpet is difficult to clean when they defecate. Timothy hay or alfalfa hay will also work but needs to be changed more readily because they are prone to mold.
WHAT NOT TO DO
Anything made from Walnut Shells, like Zilla’s Desert Blend is indeed toxic and should be avoided even if you have one of the two Blue Tongue desert species. I’m firmly against Aspen Snake bedding. Not the large shavings, but the Fine Excelsior products. It’s ill-advised because the smaller particles can get lodged in their nose and eyes when they burrow which can cause respiratory and vision health problems. It also dries out their skin. I can see a larger aspen cut working in very humid homes, but not so much in the north half of the country. Sand by itself is bad because it can get impacted in their eyes. Paper is bad because it tends to dry out their underbelly skin more readily. Indoor/outdoor carpet does not allow them to burrow, which is a natural part of their life and should be encouraged.
A reminder to everyone reading my care section – what I have listed are my personal endorsements; don’t think to yourself you’re doing things wrong if you care for your skink differently than than the recommendations listed.
Whatever you use, be mindful of temperatures throughout the day.
In captivity, Blue Tongues go through all 4 seasons. They have a 9 months of Summer, 2 weeks of Fall, 2 months of Winter, and two weeks of Spring. These figures fluctuate as the skinks detects temperature changes in the air, in the home, and how you’re regulating their heat and light exposure. Most temperatures mentioned elsewhere online refer to summer temps. I tend to make Fall and Spring the most humid months for my Jayas. NOTE… Babies of both species experience a full year of summer or more (typically).
There are 4 main and distinctly different points to be checking temperatures. 1) They need a hot side between 80-95°F with 2) a basking spot of 110-135°F (Higher end of the spectrum for babies after their first shed. You want babies warm to the touch.), and 3) a cool side of 71-80°F. Finally, 4) ambient night time temps between 70-74°F. Because of this, I highly recommend that heat gun mentioned above, or a probe, to accurately gauge the temperature inside the habitat. Those plastic old school dials you see stuck on walls are crazy unreliable. Same with their humidity hygrometers. Very inaccurate and misleading readings. The product I recommend can be bought on Amazon.com for $11: https://www.amazon.com/ThermoPro-TP50-Digital-Thermometer-Temperature
During their cool down season, “brumation”, which will be discussed later, rules change and temperatures can drop significantly.
Because of the varying temperature zones, I find a powerful heat bulb that delivers UVA and UVB rays garners most ideal results. If you use a heat lamp, my number one recommendation is Zoo Med’s 100 watt Mercury Vapor UVA/UVB bulb. Alternative recommendations for heat include: Belly Heat by way of heat mats, heat tape, and heat wire, Ceramic Heat Emitters, and Radiant Heat Panels. If going with a Radiant Heat Panel, the only brand I trust is ProProducts. They have been around for decades, used internationally, and the only company with a perfect record of not catching fire. If you intend on underbelly heat or anything overhead as your exclusive heat source which does not output the proper UV lighting, it is recommended adding a UVA/UVB florescent light which does not generate heat. General rule of thumb is spiral bulbs are a complete waste. Better recommendations include: Zoo Med’s T8 ReptiSun 10.0 UVB Fluorescent, Zoo Med’s Zoo Med ReptiSun 10.0 UVB Compact Fluorescent Mini Reptile Lamp, Zoo Med’s ReptiSun 10.0 HO T5 UVB Lamp, or Arcadia’s brand equivalency.
Now if you live in say Florida or Arizona, or another part of the US where it is reasonable to raise your skinks outside under direct sunlight, ignore the plea below, but for most people considering keeping your blue tongue indoors, the following message concerns you… I have seen many BTS live healthy lives without heat lamps, specifically ones that output UV rays. However, I highly, highly, highly recommend providing it for them. It can be the difference between getting 35 vs 15 years out of your skink companion. They do enjoy the opportunity to come out and bask under the artificial sun part of the day. It is definitely better for the health and wellness of your skink if they have this in their habitat. It also helps their internal clock determine when day and night are. Your skink should receive 11-16 hours of light a day during the active season, and 8 hours or less, all the way down to zero, during their cool down season.
A specialty ceramic socket or Deep Sun Dome Reptile Lamp will be required for many options listed above. Standard sockets are fire hazards. Some enclosures position the socket on the side wall. Be weary of this because many bulbs need to be positioned perfectly vertical for safety and heat dispersant patterns.
If you are using underbelly heat AND a mercury vapor bulb or another heat producing bulb, please monitor humidity and temperature levels regularly. Too hot and dry of an environment is worse than too cool and moist.
If you are keeping your skink in the basement or in a home that is traditionally kept below 70- 74°F room temperature, a 75 watt nocturnal bulb or low-watt ceramic heat emitter must also be added at night. Letting the ambient temperature inside the enclosure dip below 70°F can cause them to start the brumation cycle. Constant back and forth is risky to their health, especially for a gravid female. An even bigger risk is their digestive organs cease to function below 70°F. Food sitting in their belly will start to rot and your skink may never recover. Otherwise if your home stays at least 70°F, no additional heat is necessary and just room temperature will be fine at night.
Do not use heat rocks for BTS or any reptile, really. They tend to fall asleep on them and end up burning their belly, frequently.
Zoo Med recently came out with an 80W version of the mercury vapor bulb shown above. I have been using it in my more squat habitats and find it works better than the 100W ones I had been using previously, but my largest enclosures still take the 100W bulb. You should evaluate the height from your basking bulb to substrate and determine how much power is necessary.
*UPDATE* Regarding red lights, like the one pictured above. Initially, it was believed reptiles and skinks could not see red light. That theory is obsolete. Long term exposure to red lights can damage the eyes of your skink. I am not ready to pull the plug on my recommendation that it can be of value when used only at night and only with enclosures who are kept in homes set in the 60s°F. That is when I use red lights and you know what, I find the skinks volunteering to come out and sleep under the red light. So that is my two cents. But if you need the additional heat and are still concerned, a ceramic heat emitter is great too. Again, the advice on red lights is to shy away from the main daytime heat source.
The Food Section was last updated in January 2021. New experiences, new conversations, new research, and some credit goes directly to Tiliqua-Time who specialize in all Indonesian species, and can offer more scientifically proven aspects of previously suspected dietary practices.
Food should always be washed and chopped to proportions that are appropriate for the size of your BTS. Babies tend to eat every day to every other day. Adults eat every 3-5 days. While their menu items tend to be the same, babies need 90-70% protein and adults follow a 60/30/10 or 50/40/10 rule of 50-60% protein, 30-40% greens & veggies, and 10% fruit. Because of this, babies, 6 months and under, should receive wet cat food as their staple for it’s higher protein and fat content. But at 6 months switch over to a wet dog food staple for the rest of their lives because you don’t want that extra fat content anymore. A general rule with BTS is: variety is best. You will also find that each skink has their own personality, preferences, and favorite foods. I recommend staying away from salt, frozen foods, meal (like chicken meal or beef meal), and anything rotten. There’s also a list of absolute nots below. Look for AVOID.
It is also important to sprinkle on calcium + D3 powder, known as dusting, to every meal or keep a bowl of available powder in the habitat at all times. There’s not a perfect amount to recommend here. Every skink is of different weight, may decide to eat only part of the meal, or is receiving calcium from other facets like their lights or natural sunlight. And every brand of product offers different quality and concentrate. There are things to look out for from your skink. In early development, if the tail or spine start to kink or dip, increase the ratio. At any age, if the the urates are excessively hard immediately after they are expelled, that can mean too much calcium. If there are gold flakes or crystals in the urate, that is caused by too much D3, and means it’s time to decrease the ratio – but because it is much easier to overdose D3 intake, it can be worthwhile having a “just” Calcium on hand too. Below is a calcium/vitamin combo product I use all the time.
Good To Use Anytime: Arugula, Beet Greens, Collard Greens, Dandelion Greens, Endive, Escarole, and Mustard Greens are best.
Okay Secondary Options: Basil, Butter Lettuce, Bok Choy, Green Cabbage, all types of Kale, Red Cabbage, Red Leaf Lettuce, and Romaine Lettuce are fine but will cause health problems down the line if this is the bulk staple of their diet all the time.
AVOID: Iceberg Lettuce should be avoided since it is low in nutrition and difficult for skinks to digest. Spinach should be avoided because it may give your skink an upset stomach – small amounts can be tolerated – like a few leaves in a large batch of food to feed a dozen hungry skinkerdoodles.
Dandelions and Hibiscus flowers are good for your skink to eat. Be sure to know where you are getting your flowers from. Nothing is worse than serving them food sprayed down with invisible and odorless pesticide. With that said, I have yet to get any of my skinks to eat flowers after multiple attempts.
Good To Use Anytime: Acorn Squash, Butternut Squash, Cactus pad/leaf, Green String Beans, Spaghetti Squash, and Winter Squash are best.
Okay Secondary Options: Asparagus, Beets, Bell Peppers, Brussels Sprouts, Carrots, Cauliflower, Celery, Corn, Cucumber, Green Peas, Okra, Opo Squash, Parsley, Sweet Potato, Radish, Yellow Squash, and Zucchini are fine but will cause health problems down the line if this is the bulk staple of their diet all the time.
AVOID: Onion and Rhubarb should be avoided as they are Toxic to your BTS. I tend to stay away from Tomatoes, Broccoli, and especially Mushrooms as those upset the stomach of your BTS as well.
Apple, Apricot, Banana, Blackberry, Blueberry, Cactus Prickly Pear, Cantaloupe, Cherry, Cranberry, Fig, Grape, Guava, Honeydew, Kiwi, Mango, Papaya, Peach, Pear, Pineapple, Plum, Raspberry, Strawberry, and Watermelon are all okay options.
AVOID: Citrus and acidic fruit as those can upset the stomach of your BTS.
Avocados MUST be avoided as they are toxic to your skink.
Good To Use Anytime: Cockroaches, Dubia Roaches, Earthworms, Horn Worms/Goliath Worms, Moths, Silkworms, Snails, Organ Meat – like Chicken Hearts and Turkey Liver, and of course, Wet or Dry Dog or Cat Food
Never go for bugs from outside or ones you find around the house. There’s no quality control and you never know what unusual parasites they’re carrying.
With Dog Food or Cat Food, wet or dry, the rules are the same: grain-free, meal-free, high quality, and minimal salt are the best options. And the most ideal Calcium ratio is 2% accompanied by the most ideal Phosphorus ratio at 1%. With each product, you’ll need to read each label, but some brands I trust include: Fussie Cat, Merrick, Nature’s Variety Instinct, Nutro – just the ones that meet the above criteria (their company has issues on the other spectrum end of supply), PureVita, Taste of the Wild, Tiki Cat, Wellness, Weruva, and Zignature. None of these products are specifically designed for Blue Tongues so there’s almost never going to be an absolute perfect fit.
Gravy or no gravy doesn’t concern me as much as the other ingredients and criteria.
Why not Blue Buffalo brand? In 2018, allegedly, a dog died prematurely due to kidney failure. The owners concluded it was their dog’s food and tested it for elevated lead levels contaminated in the food. The class action lawsuit was recently dismissed but Blue Buffalo openly admitted they do not test their products for lead and, to my knowledge, have made zero changes to production or inspection since the lawsuit came about.
Why grain free? Skinks are natural foragers. Even though they will never come across fully cooked spaghetti squash in Australia, the nutrients are in line with their metabolic requirements and easy for them to digest. Grains simply won’t be apart of their natural diet.
Repashy brand has a few products that are great for BTS like Grub Pie and Bluey Buffet – but those can get expensive.
Okay Secondary Protein Options: Boiled Beef, Boiled Chicken, Boiled Turkey, raw or boiled Egg, Mealworms, Rabbit, and Waxworms are all fine but will cause health problems down the line if this is the bulk staple of their diet all the time.
Crickets are the most common live insect at any pet shop. Why should one not use them regularly? (1) They can carry undetected parasites and diseases. In 2008 I can personally attest to a batch of PetCo crickets killing off several of my Leopard Geckos in a single feeding. (2) They are actually high fat/low protein compared to the favored live-insect-protein, Dubai Roaches. (3) They have a high phosphorus ratio that can cause a health imbalance, putting extra strain on the skink’s kidneys. You want phosphorus to be at a 1:2 ratio with calcium, favoring calcium. Crickets are more like 3:1 favoring phosphorus.
Occasional Protein Treats include: Ham, Phoenix Worms, Pinky Mice or Rats, and Superworms can be used as an occasional treat – like a couple times a year and that’s it. We don’t want our scaled friend dying prematurely from a heart attack with clogged arteries.
Pinky’s are the delicacy to be most weary about because while the baby mice and rats were/are alive, their diet was exclusively high-fat milk. High-fat is bad for the skink heart, and dairy has no place in the skink diet. Once or twice a year will be appreciated. More might be the equivalent of deep friend pork belly for us.
I tend to use lots of ingredients with each meal. I mix it up real well so they have little choices what individual foods go down their gullet with each bite. A tutorial on one of my feedings can be seen here:
There are Five organic compounds that do not agree with your skink’s digestive system and can sometimes be fatal.
1) Persin – it is Toxic. Persin is a naturally forming fungicidal toxin found in Avocado. Symptoms can range from upset stomach to death and everywhere in between.
2) Oxalate (Oxalic Acid). Oxelates bind calcium and disallow the body from absorbing calcium, leaving the body incapable of utilizing it properly. Foods high in Oxelates to avoid are: Spinach, Potatoes (especially the skin), Soy Beans, Carrot, Raspberries, and Dates.
Foods low in Oxelates are: all types of Kale, Bok Choy, Sweet Potato, Broccoli, Blueberries, Fig, and Blackberries
3) Goitrogen is a substance that when consumed routinely in high quantities binds Iodine that disrupt function of the thyroid. High Goitrogenic Foods are: Grapes, Fig, Peach, Pear, Plum, Strawberries, and All Cruciferous Foods: Kale, Brussels Sprouts, Broccoli, Cauliflower, Bok Choy, Cabbage, Celery, Collard Greens, Mustard Greens, Spinach, Corn, Lima Beans, and Sweet Potato
Low Goitrogenic Foods are: Tomatoes, Blueberries, Bell Peppers, and all types of Squash
If you’ve already noticed a pattern of the same foods showing up in competing good and bad columns. This is where the storied confusion sets in. Use your best judgement, don’t go crazy; it’s all we can ask.
4) Thiosulphate is a toxic sulfate found in onions and garlic. This will do more than an upset stomach for your skink
5) Phosphorus. If you know about Carl and his issues a few years ago, this one hits home. Excessive phosphorus also binds calcium and as a result, taxes the Blue Tongue kidneys. A blue tongue should have approximately 1% of phosphorus in their diet and 2% calcium. If that ratio is skewed or phosphorus is just too high, the blue tongues efficient system can start to fail. Phosphorus and Calcium ratios are often flipped in dry dog food and dry cat food even so it is important to read the nutrition labels thoroughly. For Carl, I’ve just cut out all dry food and he’s been totally fine. Everyone else still eats the dry stuff. High Phosphorus Foods are: Seafood, Chicken, Turkey, Crickets, Organ Meat, Processed Meat, Mushrooms, and Banana. It is the Crickets, Mushrooms, Seafood – which is also high in mercury, and the processed meats – which are also high in salt/sodium that concern me the most on this list.
As you can see, many foods appear overlapping in multiple categories. This can help you eliminate a few but question many others. Again, use best judgement while increasing variety. Continually changing foods on them from the approved list will promote health and longevity.
This is a natural part of the adult’s annual cycle where they go into a wakeful hibernation state we call brumation. There are a few ways to do this I’ll go over. But a few things to keep in mind right off the bat. (1) Babies should keep regular summer hours and feeding schedule their first year. Occasionally a baby just might brumate and that’s okay. It was likely their biology taking over by detecting slight ambient temperature changes in the home and outside. Maintaining their light hours alone wont stop their biology. (2) Northerns naturally go through more of an official brumation than the Irian Jayas will. (3) With any blue tongue, after their core temperature dips below 70°F, food rots in their stomach. If their enclosure gets below 70°F, NO FEEDING. They will be okay not eating for 90s days. Skinny at the end, but alive and well.
The easiest method to adopt is going with the flow of your skink. You may live in a part of the country that never gets cold outside. You may live in a part that gets cold early. You may like your house warm when you’re home, but cool when you’re out. Your skink will feel these changes and burrow for days on end when they’re ready to start. When you notice this behavior, spend a couple weeks gradually reducing light hours and additional heat sources. End with all active hours cut in half. You can still feed, even though it will likely go to waste. Your skink may appear briefly now and then and want to eat. Its hard to predict these moments but you want to provide for them. However, if your home is kept in the 60s•F, then there should be not food offered and the light hours can go all the way down to zero. When the skink starts to get active again, spend another two weeks bringing everything back up to summer hours.
If you do not like the idea of brumating, a blue tongue may not be the right pet for you. Trying to wake up your skink while they’re down, or especially keeping them from getting cold, will stress them out and is a form of anthropomorphism; the attribution of human characteristics or behaviors to animals – in this case, in a negative way. Remember the brumation is for them, not for you, though I do admit to liking the break once a year personally. A further video on anthropomorphism is properly explained by Reptilian Garden, here.
Now if you plan on breeding, or just really want to experience the change boys go through during puberty, brumation practices need to be a little more calculated. The total time is an elected 60-120 days in between October – March. In this period, you lower the temperature gradually each day, while decreasing the hours the basking light is on. The idea behind this is to keep with the reptile’s natural cycle of inactivity in winter and getting ready for the breeding season in spring. I also use this opportunity to boost humidity levels even more for the Irian Jayas. Start over a two-week period by gradually decreasing the basking light hours down to 4 a day or less – even zero. If your heat source is on a thermostat, aim for a hot side of 80-85°F and the cool side can be as low as 60°F and even slightly lower at night.
When you are all done with their winter season, spend another two weeks gradually increasing the temperature and light time to their usual routine. If you are trying to breed, this warm up process can be dragged out an additional few weeks. With the traditional four weeks spent decreasing and increasing their temperature, the entire process can be between 60-120 days. I usually choose Mid November to start, and early January to begin increasing the temperature and light again. If you live in a warmer climate (not Chicago), the cool-down period may start and end earlier in a calendar year.
Yes, they do shed during brumation.
No, you don’t want to “check up on them to make sure they are okay” while they’re burrowed in silence for weeks on end. It’s like checking on a bear in their den during hibernation – you just don’t do it. Let them be animals.
A rapid way to turn on their breeding cycle is a 2 week decrease in light hours. 3 consecutive weeks of no light and no food. Hot side gets up to 69°F during the day and cool side gets down to 49°F at night. And then an extended, gradual light increase while you attempt to pair as many as you can get before the males tap out.
A warning about brumation. When the skinks core temperature drops, their immune system becomes susceptible to bacteria and illnesses their body would otherwise be fighting off without notice. When your skink gets into their 30s, this is usually what takes them. The lower temps go, the higher risk it can be.
Indonesian subspecies experience less of a temperature/light swing than their Australian counterparts living so close to the equator. They experience more of a dry/wet season shift. When I decrease light and temperature for everyone, I keep more light hours on with the IJ than the Northerns, and add additional moisture to the habitat. When I do this while decreasing the temperature, I have to till the soil more regularly to keep from mold and other harmful bacteria conditions from forming. A trick to getting Indo species to cooperate during breeding season is to simultaneously boost humidity levels while dropping the temperature and decreasing light hours leading to their cool down cycle. It’s a tricky process doing this while avoiding a breeding ground for mold.
SEXING AND BREEDING
A general rule is: All BTS are boys until you see babies squirt out the rear.
Sexing is incredibly difficult for the blue tongue skink species. Because they give live birth and do not have a vent, there is no great way to determine their sex, especially before adulthood. There are general guidelines for determination, accompanied by a fair share of anomalies. Females tend to be slightly larger and less aggressive than the males, but just like in humans where you can have a tall, angry lady, or a small, submissive man, that generic rule can be fairly useless. That same mentality to be applied to the rest of their physical characteristics. Females tend to have wider hips to accommodate the birthing canal and the males tend to have a larger tail base (that’t the end near their butt) to accommodate the hemipenes. It is hard to catch sometimes, but males will drop sperm plugs during the mating season if they do not have a female present, especially just after coming out of the cool cycle. If you have an adult male, it is physically possible to pop out their hemipenes to see them. There is nothing to pop out in a female. If this is done wrong it will damage your skink. I do not recommend it, have never done it myself, nor plan on doing it. But if you feel you are up to the task, there is a video is on Youtube by Zooman Adventures.
Below is a video Joe Ball made, going in depth about ways to sex your adult blue tongue. If you’re unaware, Joe Ball out of Australia, is breeding some of the best blue tongues available on the planet.
If you have multiple skinks at your disposal, and want to see how they interact with other, please supervise at all times. If both skinks are sexually mature, and recently coming out of brumation, their behavior should indicate their sex. Generally, two females will mostly ignore one another, but aggression is possible. Two males will definitely be aggressive with one another, unless you luck out with the most amazingly docile skinks out there. And the opposite sex will usually indicate at least one interested in the another.
First, let’s go over some of the risks and pitfalls. (1) You can do everything right and the male or female still isn’t interested in breeding. (2) Minor cuts and bites lead to scaring post mating. In 2019 George took a bite to the face from Big Mamma and had a black eye for about 6 months. I feared he may have lost it. (3) Loss of limbs. If someone goes for a death roll, expect an arm or leg to tear off. Same goes for a tail. (4) The female dies during child birth or during pregnancy. Not only that, but all her babies die too. (5) The male is unable to get his hemipenes back inside. (6) Babies are born with severe deformities and it’s up to you to cull them and dispose of the bodies. Cull means to humanely kill, FYI. About half of these require a vet visit with a bill encroaching on a grand each time. Still feeling like breeding is your thing? Please continue below.
Blue tongues are choosy with their mates and creatures of habit. If they are to mate, the female will remain still but start to wag her tail in a come-hither motion. This only happens though if she’s interested in mating and likes the bloke. Peeing and running away indicate she is apprehensive towards the male and not ready to breed. The male will become highly alert and wait for the indication that he is in the presence of a willing female. If he receives an invitation from the female, he will likely race towards her and aggressively nibble at her. Their copulation tends to be a bit aggressive as the male tries to have his way with the female in attempt to gain position. Their copulation may be as short as one minute and potentially longer than 25 minutes.
Here is a sample video I made of the copulation: Dave’s Skinks Instagram
Remember when I said all BTS are males until you see babies squirt out the rear??? That is because an aggressive male may have his way with a more submissive male. Yes, homosexual copulation does take place within BTS society. If you are waiting around for months for babies to appear, you may be in for a rude awakening. Submissive males will even have a spike in hormone imbalance that triggers a false appearing pregnancy.
I recommend matching up your mating pair at least 3 times to ensure she is gravid if you hope to have babies. And you may want to encounter your BTS with a handful of other adult BTS to ensure you indeed have the sex you suspect you do.
If you get a gravid female, she will give live birth to anywhere between 0 and 24 babies… Yupp. Gestation may be as short as 85 days and potentially longer than 165 days, especially for the Indonesian species. Also keep in mind, the female can maintain viable sperm for months before interacting them with her reproductive system. Frankly, breeding is a little like playing darts in the dark.
The term “Slugging Out” refers to a delivery of 100% unfertilized ovum. This happens when the copulation triggered fetal development in the female, but no male swimmers made it to the eggs, resulting in this type of pregnancy. Healthy delivered litters can also be accompanied with some “slugs”.
If you can monitor the birth, I recommend it. The babies are born in a thin membrane that needs to be removed for them to breath. If they do not figure it out on their own after a moment or two, you can gently rub it off of them. Otherwise the membrane may suffocate them. It is also important that the babies eat their own placenta as a first meal and may need help getting it into their mouth. Mom will usually be a good mom for the first 24-36 hours after the babies are born. But after that she may get territorial and think of them as food. The babies will be active immediately and looking to eat. Birthing a litter can be quite hard on mom. If she struggles, consider breeding her every other year. She may also give birth to a hardened yellow ball. These are unfertilized eggs; normal, edible, and affectionately nicknamed – slugs.
PROBLEMS YOU MAY ENCOUNTER
If fingernails get too long, they will actually continue to grow, curl underneath the hands of your skink, or out to the sides and make it very uncomfortable for your skink to walk. This is a sign it is definitely time to trim their nails, manually. Be wary of their quick. Cutting into their toenail vein is painful and may result in loss of the toe.
With each shed you want to do a thorough inspection of their toes as well. This is the most challenging place for a skink to relinquish 100% of their old skin. It tends to blend in too, especially when covered with dirt. The littlest ring of shed skin can cut off circulation in days. This can lead to a loss of toe or a growing infection. Tweezers are a good friend.
There are various health problems associated with these species. Some include: mouth rot, metabolic bone disease, worms, eye infections and ticks. I have never dealt with any of these personally so therefore do not feel comfortable best advising you how to handle it. I would encourage your own Internet research and seek a professional veterinarian if the condition looks serious or persists what so ever. You can find a qualified veterinarian near you by using the Association of Reptile and Amphibian Veterinarians (ARAV) search tool. An additional resource on Blue Tongue Skink Diseases can be found here.
On one occasion, Gladys, one of my Irian Jayas had a bulge in the corner of her eye. It was likely a poke from the woodchip substrate. I put her in a quarantine tank on paper towels for a few days and the problem naturally corrected itself. Had it gotten worse or persisted for more than a week, a vet visit would have been required.
Carl, a Classic Northern produced by reputable breeder, James Wilson, started getting swollen back legs. He dropped some weight and started getting aggressive. If I tried to touch his back legs, it appeared to be painful for him. This lead to my very first vet visit for a Blue Tongue Skink. I used the Association for Reptile and Amphibian Veterinarians FIND A VET tool to search for local, approved veterinarians. I called around and scheduled an appointment with the office I felt most comfortable with. Something to keep in mind with these specialists vets. (1) They have a for profit-business to run. (2) They don’t get as many customers as other veterinarian offices do. (3) They likely know a hell of a lot more about animals than you or me, but not specifically as much about Blue Tongue Skinks, especially the particular sub-species you bring to them. Think logically about the services they are offering to you. If you bring in your skink with a skin issue on a limited budget, consider what I mentioned above as they propose x-rays be taken. Don’t be afraid to take charge in the office when managing your skinks health care. In my case, I cut out roughly $1000 in suggested testing, and they were still able to sufficiently determine Carl’s kidneys were not functioning properly. He had too much phosphorus in his diet. Skinks need a diet of 2% calcium and 1% phosphorus. After reviewing the Merrick wet dog food and Acana dry dog food I was using, I noticed these ratios were closer to 1.2%-1.6 calcium and 1% phosphorus. That little difference was all it took to throw Carls system out of whack. Even though I was sprinkling on calcium powder with every meal and Carls brother from the same litter was perfectly healthy along with all of my other skinks, for this one of my 10 adult skinks (at the time), a diet change and some temporary medications were in order. I proceeded to test different dry dog foods, but Carls issue persisted. After speaking with a knowledgable associate at a trusted specialty pet food store I frequent, I was informed when cats have kidney issues, the common recommendation is to cut out dry foods entirely. Overall, they are harder for kidneys to filter. Another round of Alternagel Susp. and Baytril medications and Carl’s back to normal. He is no longer given dry dog foods of any kind and is doing just fine. Had I known of this sooner, it could have saved me a $625 vet bill + $75 of alternative dry dog foods. I hope an issue like this never happens to you or your skink, but if it does, perhaps there’s a chance to save $700 while keeping your skink in tip-top-shape.
In recent years, especially with the Northerns, prized pattern morphs have come out due to bloodline lead traits being expressed via inbreeding. The inbreeding of genetics may result in a cool pattern, but can cause a kinked spine, kinked tail, or over and under bite jaws, and a naturally weaker immune system . No matter the appropriate calcium levels and other superb husbandry, not much can be done about shallow genetics. They also tend to be smaller in size and if they never reach 500 grams, it is ill-advised to breed such a small female.
DIFFERENCES IN SKINK CARE: NORTHERN VS IRIAN JAYA
For me, with the natural climate and humidity levels in Chicago, the particular display-style habitats I chose to go with, along with the substrate and heating combo – there are only a few differences in care I enact that caters uniquely to each subspecies.
1) Indonesians need higher humidity. To accomplish that, I add a higher percentage of coconut husk, mossy substrates, and play sand to the hot side. I also add more water to the enclosure more frequently more frequently. Say 3 cups instead of 2. I keep the Northern humidity at 40-60%, being on the higher during shedding. And 60-70% for the Irian Jayas, potentially up to 80% during shedding. The above mentioned humidity readings are average levels. And levels calculated at the floor level your skink might be. If you take a reading close to the top of the tank, it will be different than what your skink experiences. It is okay if there is a spike up to 90% for an hour when you add the water initially, and there can be moments during peak day heat where it gets as low as 30%. As long as it consistently remains in the range that is good, fluctuating spikes at particular moments of the day shouldn’t be anything too concerned about.
2) During the summer months, I may keep lights on the Northerns 12-13 hours or so. But the Indonesians will get 14-16.
3) During the cool down cycle, I may drop Northern light hours to 4 or even zero hours a day. With the Indonesians, it may be as high as 8, but can also go as low as zero hours a day. They also get another bump in humidity then. Keep in mind, I am trying to get them on a breeding cycle here. If that is not your objective, nothing needs to be as extreme or precise. Please review what was previously mentioned in the COOL DOWN/BRUMATION section in addition to these three distinctions of care.
That’s really it.
For each lizard though, I make personal adjustments based on their hydration. Every skink takes in water differently. Some like to lap it up from their bowl, others prefer to burrow when the substrate is moist, others like to hover over the top for a steam affect. Some prefer to remain burrowed the entire time, others prefer life on the surface. If all conditions are the same in each habitat, some lizards may appear more dry than others for these very reasons. If you skink’s belly is rough, their sheds are flakey or their skin looks cracked, you need to allow more options for your skink to intake water and bump that humidity.
For anyone who says they keep their Northerns at 20-40% humidity, or they keep their Irian Jayas just like Northerns, they are flat out doing it wrong. No apologies. There is a lot of misinformation out there and their skink is alive. Yes alive, but suffering. Any BTS can live over 30 years. Improper conditions, like smoking cigarettes for humans, take time to effect the lungs. When your blue tongue looks like a dry raisin at age 16, dies prematurely, and has bad lungs at autopsy – this is the reason why.
ADDITIONAL CARE AND OTHER IMPORTANT FACTS
– They can switch to a more adult themed died after 6 months, but may continue the high protein diet the first two years.
– Though they will continue to shed and grow their entire lives, 90% of their total growth is done the first 2 years.
– Nail maintenance is a must but should be done naturally by them walking over the rocks, brick, and slate you already provided for them.
– The more you handle them the more personable they will be and bond with their hooman.
– Always support their entire body when handling them. Particularly the shoulder and hip areas.
– Their hissing sound is actually a heavy breathing and usually an indication they are not interested in being handled at this time but their mood may change once they are picked up.
– An open mouth is a sign that an aggressive and defensive bite is coming. Time to leave alone.
– If their eyes are closed when petting they may be falling asleep, but more likely they are stressed out. Reptiles are not like mammals. Mammals close their eyes when they relax. Animals close their eyes as a mform of sensory deprivation because what ever is going on is overwhelming and inescapable.
– They have a tiny black dot on top of their head in the center. This is a third eye, called the “parietal eye”. It is light sensitive. And just like an eyeball, should not be touched or rubbed by you.
– If they make an “arf” type of squeak, they are under distress and need to be attended to instantly.
– Interactions with other animals is generally risky. Cats are potentially the safest. Other reptiles may seem like a safe idea but each reptile has their own unique oils and touching skins of different reptiles can be health hazardous.
– Feces should be picked up daily. Their feces have two parts consisting of the traditional brown log and an additional white byproduct. The white byproduct is “uric acid” and is how their body expels sodium. Feces left in the habitat will attract mites.
– If you are using natural substrates, a helpful bug called springtails may appear. They are like an in-house cleaning crew and will not harm your skink. Do Not confuse springtails with harmful mites – they look different to the trained eye. Springtails are typically oblong and grey with antennas. Mites are super tiny and round in comparison. They come in white, black and red.
– Water should be changed at least every week and sanitized when they defecate in the bowl.