EASTERN Care Guide
CAPTIVE MANAGEMENT OF
EASTERN BLUE TONGUE SKINKS
By TC Houston
Animal welfare is absolutely the most important part of maintaining reptiles in captivity. As reptile keepers or pet owners we are responsible for the entire lived existence of these beautiful, sentient, and intelligent creatures.
Every keeper has to start somewhere and often that start includes very basic care which is understandable. However, basic care is not the end state nor is it an acceptable stopping place for very long. Progressing up the reptile welfare chart (shown here) is not only good and appropriate it is expected. Please review this chart and take note of the very basic care guide provided below.
Tiliqua (Blue Tongue Skinks) are terrestrial animals, meaning they live almost exclusively on the ground. Their bodies are designed to move quickly and efficiently through the first layer of strata making them almost fossorial in nature. Therefore, they need surface area rather than height when considering housing.
Easterns are only slightly shorter and thinner than their Northern counterparts and a single adult animal can survive in the U.S. hobby-wide MINIMUM, a 40 gallon breeder (36in. long X 18in. wide), or at MINIMUM 4.5+ sq.ft. floor space. However, a larger space is recommended and preferred by most keepers.
An enclosure size of 8 square feet of floorspace or larger is OPTIMAL for any blue tongue skink species regularly available in the trade.
I recommend the 4 x 2 x 2 PVC enclosure or larger from Kages Custom Reptile Enclosures (ReptileKages.com) for permanent adult housing. There are many other custom enclosures available that are excellent as well. I use Kages enclosures with 6-8+sq.ft. of floor space per animal and a custom system I constructed myself.
Please keep in mind that each animal is an individual with individual growth, terminal size, behaviors, and predispositions. Therefore, some animals may need larger enclosures and some may need smaller or less “open-view” enclosures to thrive. Part of reptile keeping is learning the balance between the biology/science and the art of adapting to “what works” for the individual animal. Flexibility and observation are the most important keys aspects to keeping any animal.
IMPORTANT: Some Eastern Blue-Tongues can cohabitate HOWEVER new keepers should NEVER house their skinks together! Tiliqua can extremely territorial, defensive, and even aggressive toward conspecifics. They should only be placed together for breeding purposes under DIRECT supervision for short periods of time or by EXPERIENCED KEEPERS who know how to read behavior.
Feeding & Diet
In the wild blue-tongue skinks eat mostly land snails, carrion, insects, wild veggies, berries, fruits, and plant materials. They are not cunning predators but rather general omnivorous opportunists. Babies are more carnivorous/insectivorous for their first season/year of life.
Due to the omnivorous ingredients in many cat and dog foods a majority of breeders and keepers feed their animals cat or dog food as a staple (aka over 50% of the diet). I feed my blue tongues a variety of dog foods, cat foods, Bluey Buffet by Repashy and Omni Gold by Arcadia. I also supplement adult dog foods with 50% Healthy Herp Veggies or fresh diced greens and veggies.
Note on FOOD DENSITY:
Understanding food density is important to ensuring optimal health. For example one cup of dry dog kibble might have 3 times more protein and nutrients in it than one cup of wet dog food. Why? Because of the moisture content. Moisture content helps reduce density and increase hydration. Many species (Tiliqua included) will gain water from their food intake in addition to drinking (drinking when thirsty does NOT provide adequate hydration). Feeding highly dense foods can cause stress on an animal's liver, kidneys, and digestive system creating subtle problems that will shorten the life of your skinks. No you can't simply soak the kibble. Unfortunately, although better than not soaking, the process of soaking kibble only provides about a 1:1 moisture ratio which isn't the same as wet foods. Therefore, wet food is best suited for aiming toward an optimal diet. However, just wet dog food is also too high/dense in proteins and fat...which again will not only stress the organs but can lead to gout and fatty liver disease. So that is why I recommend an adult skink maintenance diet contain 50% vegetation. These foods are higher in fiber and high in water content making the "as fed diet" less dense. Promoting lean, healthy, and hydrated skinks.
Adults (1 yr +/ 400g+)
Wet DOG food with veg/ Bluey Buffet/ Omni Gold
1 x per week
Sub-Adults (6mo – 1yr /300g+)
Wet DOG food/ Bluey Buffet (once a month)
2-3 x per week
Juveniles (2-6mo/ 100g-300g)
Wet CAT food/ Bluey Buffet (once a month max)
Every other day
Babies (0-2mo/ 15-100g)
Wet CAT food/ Bluey Buffet (once a month max)
I give them a serving the size of their head or a bit bigger as a rule of thumb.
High Animal Protein content
Variety of Fruits and Veggies (little to none for babies)
Turnip greens, Mustard greens, Summer/Spaghetti Squash
Keep fresh (freeze if needed)
Calcium (Calcium carbonate or tricalcium phosphate)
Vitamin D3 Supplement
Adult Foods I Feed (1 yr +)
Whole Earth Farms Grain Free Hearty Turkey and Chicken Recipe Wet Dog food
Nature's Logic Wet Turkey/Chicken Formulas Dog foods
Ziganture Wet Turkey Dog Food
Arcadia Omni Gold Earth Pro Series
Repashy’s Bluey Buffet
Variety of Greens and Veggies (Turnip & Mustard Greens, Butternut & Spaghetti Squash etc.)
Blueberries/Edamame/Banana/ Pinky Mice (pre-killed) all on OCCASION as TREATS
Fish (including fish oils)
Starchy fillers (potatoes)
Chunky or Large bite sizes
Spinach (a little is okay)
Baby Foods I feed (0-11mo)
Halo Gluten Free Natural Wet Cat Food, Indoor Turkey & Quail Recipe Wet Cat food
Nature's Logic Wet Turkey/Rabbit Formula Cat Foods
Wellness CORE Grain-Free Turkey, and Duck formulas Cat foods
Wellness Grain-Free Turkey Pate Cat Food
Most blue tongues do well with 12-14 hours of light per day for overall health. Ultraviolet Light Wavelength - B (UVB) has been linked to psychological and physiological welfare in many vertebrates and can be provided artificially for premium wellness in skinks. I must note that I am unaware of any behavioral studies regarding the impact of UVB on mental health in blue tongues skinks to date. Thus, providing UVB for psychological health is purely conjecture. Despite the lack of evidence for mental welfare I choose to provide UVB to my skinks for the overwhelming physiological health benefits.
The bottom line: UVB plays a vital role in overall energy utilization, including but NOT LIMITED to Vitamin D3 synthesis in a majority of terrestrial vertebrates such as blue tongue skinks. Without vitamin D3 the lizards CANNOT absorb calcium and thus their bones will not grow strong but rather horribly weak and can eventually develop metabolic bone disease (MBD) which is horribly painful and can be fatal if unaddressed. Getting Vitamin D3 into an animal's system can occur through two avenues;
1) appropriate UVB lighting
2) dietary provision.
Both ways, if provided correctly, can be very successful in achieving satisfactory 25(OH)D3 aka hydroxyvitamin D levels. HOWEVER, the physiological benefits of UVB light has proven to be THE MOST EFFECTIVE artificial avenue to providing OPTIMAL animal regulated 25(OH)D3 levels in the blood . This gives the animals an increased influence over 2,000 genes impacting a huge range of functions, including cell division and the immune system (source). Thus, I keep my breeder skinks with linear T5 HO 5.0 UVB bulbs from ZooMed giving them the UVI (Ultra Violet Index) needed to maintain natural levels of 25(OH)D3. Still, because of the sheer numbers and space challenges I do raise babies for short periods of time without UVB and use dietary supplementation alone.
How much UVB to provide?
The amount of UVB light present is determined by what is called the UV Index (UVI). This is measured by device called a Solarmeter 6.5 and/or 6.5R (R= reptile, meaning there is a lizard sticker on the device, purely a marketing thing). Every animal has a different amount of UVI they need at their basking site. Herpetologist Dr. Gary Ferguson and his research team created a system called the Ferguson Zones that help categorize species based off their UVI needs in the wild. The Soloarmter 6.5 helps keepers determine if their animals are getting the correct UVI from their bulbs. If you don't have a Solarmeter be certain to follow the manufacturer's guidelines for bulb strength and placement.
Blue Tongues are "Intermediate" Ferguson Zone Animals Requiring:
Between Zones 2 - 3
1.1 to 4.0 UVI (UV Index)
I aim for 3.0 UVI
UVB IS HIGHLY RECOMMENDED AND PROVEN TO BE THE OPTIMAL METHOD OF Vit. D3 PROVISION
I highly recommend using UVB. If used, be aware bulbs require changing about every 6 -12 months or so (unless stated on the package). There is mercury inside these bulbs that allows for the production of UVB that breaks down over time and thus one must replace the bulbs semi-annually regardless if they are still emitting light. There are different kinds of UVB light bulbs provided to the hobby because there are animals that have different basking behaviors and UVB requirements for psychological and physiological uses. Some animals, such as bearded dragons, require high levels of UVB (aka a higher UVI) because of the way they live in the wild (basking all day in the high noon sun). Some animals such as, blue tongue skinks, use moderate to lower levels of UVB (aka a moderate UVI) because they bask in the early morning and afternoon/evenings when the UVB output from the sun is less. Using the right UVB product will ensure the best outcome for your skink.
I recommend the 10.0 T5 HO tube versions of UVB if used above a fine (<1/8 in.) screen or glass if you intend to use the light for D3 synthesis purposes. It is important to know that UVB bulbs only project UVB a specified distance from the bulb’s surface to they often need to be within 18” and not closer than 6" from of the animal’s skin to be their most effective. Be certain to follow the package guidelines or ideally use a Solarmeter 6.5 to ensure the correct UVI is present for your animal. I use the ZooMed T5 HO Linear 5.0 15w bulbs for my adult animals in the custom rack system.
If you chose to go with UVB as your source of D3 I recommend providing additional dietary supplement of Vitamin D3 once a month or a low D3 percentage calcium product routinely because these animals are omnivores and do ingest dietary D3 through animal protein consumption in the wild.
I have seen far more animals develop MBD due to incorrect use of UV use than with incorrect dietary supplementation.
Heating & Temperatures
Tiliqua are ectothermic (cold blooded) and need to use their environment to regulate their body temperatures for digestion and overall healthy body functions. In captivity it is the keeper's responsibility to provide the correct environment. The key here is to provide a thermal gradient that allows the animal to move back and forth from warm to cool so as to get the right temperature they need. In order to do this having one end of the cage approx 1/3 of the space warm/hot and the opposite end cool/warm is idea.
The ideal temperature gradient for Tiliqua scincoides scincoides is 90F-95F on the warm end and 70-75F on the cooler end with a basking spot of 98F-100F.
I have not found that a night temperature drop is required. If a night temp drop does occur (intentionally or not) I have found that ensuring a night warm area of 80F is provided and not allowing the cool area to drop too far below 60F is important for respiratory health.
Reaching the appropriate temperature has multiple variables including but not limited to room temperature, house hold humidity, room air flow, cage material, cage size, location of cage to others, and type of thermal element used to provide heat. Finding a good heat gradient is where the real “herpetoculture artist” within the keeper is tested. You may have to “play with or fiddle with” your elements until you get the right temperature range. This can be done by increasing/decreasing your settings on thermostats, changing bulbs/CHE (Ceramic Heat Emitter) to higher or lower wattages, increasing or decreasing the distance the bulb/CHE is from the basking surface and much more. For this reason the purchase of a temperature gun to get fast accurate surface temp readings is essential. On this site under the “Resources” tab you will find a link to supplies I use/ recommend including the temp gun.
Important HEAT NOTE: I recommend using a halogen PAR floodlight bulb that is on a light dimmer for an over head basking area/heat source. The key words here are “halogen” and “floodlight.” This is crucial as halogen bulbs produce the proper light waves to penetrate your animal’s torso with heat. Other forms of bulb or emitter DO NOT DO THIS and only heat the animal’s skin surface which is insufficient. Also, floodlights typically have a glass that refracts the light to disperse evenly over a broader space so as to maximize the amount of physiological heat penetration.
Tiliqua need a constant fresh water source which can easily be provided by giving them a heavy shallow water dish that holds 4-8 ounces of water. A bowl that is between 1-2 inches tall is best. The bowl should be heavy or at least difficult to spill as Tiliqua will tip over any lightweight or unstable water bowls. Blue-tongues will get bedding in their water and new fresh water should be provided often.
The Australian species (Easterns especially) do not need high humidity. They do very well with 30%-50% relative humidity. They can handle up into the high 60 percentages as long as there is good ventilation and their soil is not wet. Keeping them too wet or too dry can cause health issues. Most typical U.S. indoor environments have good humidity without needing anything extra. Sometimes in the very dry winter months animals will get dry belly scales. If your animals are kept on cypress mulch a simple fix is to spray down the bedding lightly once a day to prevent dry scales. Another option is to use a humid hide which is a 6-15 quart plastic shoe box with a hole cut into the side big enough for the animal to fit through. Inside the box place damp sphagnum moss and place the lid on securely. The moss will hold the moisture for at least a week and the animal can climb inside like a mini “sauna” to gain moisture as needed.
NOTE: Blue-Tongues are not swimmers. They can swim but out of pure survival and need. They do not need to nor should they be placed in water deeper than one-half (1/2) inch. With proper husbandry these animals should never need to be "soaked" like a snake. Even with a stuck shed a good humid hide is all that should be required.
I keep my Easterns on one of two things, pure organic cypress mulch (ZooMed's Forest Floor) or coconut husk chips (ReptiChip/ProCoco) as a substrate. Many keepers have found that cypress, coconut husk chips, orchid bark (ReptiBark by ZooMed), and aspen shavings all work well for Eastern Blue Tongues. I use cypress/coco husk chips because it can be misted and hold humidity as needed. I elected to use coco husk chips primarily because it is less expensive and in Colorado the air is so dry that I needed to have a substrate that can hold some humidity which is not the case with Aspen style beddings.
All reptiles need a place to feel secure and completely out of sight in order to maintain peak psychological wellness. Easterns in particular can be shy for some time before getting comfortable with their new homes. Providing a “hide” or place to be completely out of sight is essential to caring for any reptile including skinks. I provide hides in a couple of ways. One way is to use timothy hay/ straw piled up whereby the animal can bury themselves out of sight. Another option is to use commercially available plastic or wood hides. I use corrugated plastic tubing “T-connectors” from the hardware store and modify them with a drill and zip-ties
Reptiles in the wild are not designed to cohabitate with humans or other predatory type animals such as cats and dogs. Constant presence of such animals in view of a skink can cause unhealthy levels of stress. For example, a cat sitting outside the enclosure all day long or an enclosure low to the floor in a high traffic area where lots of fast movement is observed can cause serious stress that accumulates. Sometimes even a well-adjusted animal can slowly (over a period of weeks/months) become overcome by stress and develop other health issues from a compromised immune system.
Keeping other pets away from view as often as possible and keeping enclosures out of high traffic areas can help ensure your reptile’s long term well being.
Reptiles, even blue tongue skinks, are not “snuggle buddies” in the sense that human interaction and touch is something that contributes positively to their emotional health which is unlike social animals such as dogs. That being said some individual skinks will respond well to human interaction and exhibit the appearance of enjoyment when exploring their world and those in it, including people. It is important to think like a skink and not for a skink in these situations.
Ensuring that interactions with people are positive includes looking for calm breathing, smooth inquisitive movements, and steady calm tongue flicks, etc. It is important when handling or interacting with any reptile that time be a consideration as well. Most reptiles are not “marathon” type athletes and rather they need to rest frequently to recover from activities, and blue tongue skinks are no different. Allowing interaction/explore time to be limited to 10-30 minutes a day is appropriate.
Also, observations of rapid breathing, frantic movements, consistent frequent or rapid tongue flicks, or seeking cover are signs the animal is experiencing distress and needs to be returned to their enclosure and left alone for 24 hours minimum.
While holding your skink do not hold them by the tail or squeeze their body as this can cause harm or even tail break (caudal autotomy). They do not do well when restrained in general and it is not necessary for handling, I have given my skinks injections of mediation without requiring restraint. They need to be able to loosely move through your hands. It is important to support their torso and if possible allow their feet (at least 2 at a time) to have support so they are not dangling. Once they feel comfortable they may relax and allow their feet to hang off you.
Flighty babies and juveniles need to be held over something soft and not too high in case they leap or jolt and end up falling. Serious injury can occur from a fall. I know of a few keepers who have had skinks break their jaws from accidental falls.
Enrichment is a critical element to your reptiles' welfare.
In the past the term enrichment has been dismissed by reptile keepers due to their lack of understanding of the reptilian brain and the goal of enrichment itself. Sadly many keepers misunderstood enrichment to be an attempt at bringing happiness to an animal. Yet, in reality enrichment for reptiles has nothing to do with making them “happy” and everything to do with helping them be healthy. Let me say that again… enrichment is not about “happiness” yet rather healthiness.
Simply put, enrichment interventions are additions to an animal’s lived experience that contributes toward optimal health both physiologically and psychologically. It helps me to think of an animal’s brain as a massive collection of on/off switches whereby each switch has evolved to be present in the animal for some utility purpose. Animals under captive management (our pets) have a different lived experience from that of their counterparts in the wild and don’t always get those “switches” turned on and off. However, the presence of a switch means it should be used. Of course not every switch needs to be turned on or off the same amount or intensity...yet they all serve a purpose.
Thus, the closer an animal is to utilizing its organs to the fullest appropriate capacity (including exercising the brain) the healthier the animal.
Below are a set of commonly identified modalities for enrichment in captive animals. These help keepers to target different “switches” and set our pet reptiles on a path toward optimal health.
Note: Not all these examples are appropriate for Blue Tongues.
Sensory - Sights, smells, textures, experiences, tastes
Food/Feeding - Food types, flavors, textures, methods
Cognitive/Manipulative - Problem solving, puzzles, climbing, digging, swimming, soaking, burrowing
Environmental - Lighting, Airflow, spatial arrangements, moisture, sticks, logs, rocks, plants, soils, temperature
Behavioral/Social - Engagement with conspecifics, engagement with other species, breeding, hunting, foraging, training, choice
Blue tongue keepers and reptile keepers in general should dig into their creative tool box and develop randomized species appropriate enrichment opportunities in each of these modalities so as to routinely enhance their animal's lived experiences under captive management.