There are many different subspecies of the Blue-Tongued Skink, and with this comes some differences for how to care for them in captivity. The information shared in this article is an overview for how to care for Blue-tongued skinks. It is important for keepers to research the specific subspecies they are keeping.
Blue-Tongued Skink Lizard (Tiliqua scincoides scincoides) averages 45cm in length but can reach 60cm. In the wild, they are known to feed on small animals, insects, carrion, and plant material.
They are commonly found in suburbia and do well in captivity, therefore making them fantastic pets. They give birth to live young and, on average, produce 6-12 offspring, but larger numbers have been recorded.
What Is the Blue-tongue Lizards’ Natural Environment?
Blue-tongued skinks have adapted well to woodlands, bushland, suburban and even urban areas, often inhabiting backyards.
What Is the Average Lifespan of a Blue-tongue Lizard?
Blue-tongued skinks have been known to live up to 30 years but average 15-20 years in captivity.
How to Handle a Blue-tongue Lizard
Blue-tongued skinks are docile and tolerant to handling, which has allowed them to become popular pets. With careful handling, they can tame easily. It is important to support the centre body of your blue-tongued to minimise stress and reduce the risk of dropping or injuring them.
Although it is uncommon for blue-tongued skinks to bite, human fingers can sometimes be mistaken for food, and an accidental bite with their powerful jaws can be very painful.
Never grab a skink by the tail. Many skinks can drop their tail with a process called tail autotomy. Tail autotomy occurs as a defense mechanism, and although the tail will regrow, it will be at a large cost of energy and will not be the same as before.
Husbandry Tips for Blue-tongued Skink Lizards:
The enclosure for an adult, Blue-tongued skink, should measure no less than 120-180 cm long (4-6 feet) and around 45-60 cm high (1.5-2 feet), but larger is ideal. Good ventilation is essential to manage air circulation, temperature, and humidity. It must be secure, and it is recommended to keep it out of draughty areas.
When picking the enclosure, consider how you will achieve the Preferred Optimal Temperature Zone (see POTZ further down), lighting requirements, humidity, hiding spots, basking areas, air circulation and environmental enrichment. The enclosure should be cleaned and disinfected regularly, and the materials it is made from should not absorb moisture.
The preferred disinfectant to use is known as F10 SC which can be diluted 1ml concentrate for every 250 ml of water (1:250 dilution). All debris must be cleaned out first. The solution will need to stay on the area for a minimum of 15 minutes or based on the companies’ product recommendations, for the required disinfecting time of the organism in question.
Blue-tongued skinks should be housed alone. Even juveniles are known to fight, causing severe injury to each other.
There are many suitable substrates, and they all have their good and bad properties. Substrates often used include sand, peat, bark, leaf litter, recycled paper pellets and critter crumbles. These all tend to have issues with water absorption and can be challenging to clean.
Newspaper, butchers’ paper, or paper towels are easy to clean, pose no risk for obstruction but do not allow for digging, look unnatural and absorb humidity poorly. Aspen, hemp or vermiculite can be used and do well with humidity while being easy to spot clean. Reptile carpet is another option, but ensure a replacement piece is handy to allow regular cleaning. Any water spillage needs to be addressed immediately.
It is important to consider the different aspects of the substrate to suit your particular enclosure. Having a conversation with your reptile veterinarian can help you choose the most suitable substrate.
In addition to the main substrate, having a rough surface, such as a slate tile, in part of the enclosure will help to keep your blue tongues nails from overgrowing which is a common problem we see.
To reduce stress and to offer shade for your Blue-tongued skink, hiding areas should be provided. This can be accomplished using hollowed-out logs, purpose-built containers, paper towel rolls or PVC tubing. Branches and rocks can also be provided to aid in shedding. Although your blue-tongued skink has short legs, it can climb over these obstacles quite well.
Whatever you choose to furnish the enclosure, be sure that it can be easily cleaned, replaced and is secured so as to not fall and injure your skink. It is important to avoid over crowing the enclosure with items. Similar concepts can be used for outdoor enclosures.
Using non-toxic plants to give shade and dappled sun areas will help with providing a gradient of temperatures. In outdoor enclosure set-ups, there must also be an area of permanent shade that can be always kept dry.
It is recommended that you supply a day-night cycle for your Blue-tongued skink of 12 hours of light and 12 hours of darkness. Adjusting this cycle to match natural cycles is also possible and may contribute to more natural behaviours.
Full-spectrum lighting containing ultraviolet B radiation (UVB; 280–310 nm) and infrared heat (basking area: 34–36°C; 93–95°F) is recommended. These provisions are needed to ensure proper metabolic function and development. The UVB output will degrade over time and requires routine replacement every 6-12 months, depending on the manufacturers’ recommendations. Alternatively, the UVB output can be measured using a radiometer.
At The Unusual Pet Vets, we offer a service where bulbs can be tested to ensure adequate UVB is being provided in your skink’s enclosure. This service can also help you save on bulb costs over the life of your skink. Remember, UVB not only needs to be available but also needs to be accessible. Therefore, the light will need to be positioned where your Bluetongue is basking and at an appropriate distance where the UV will still reach your lizard.
The recommendation of strength of the bulb and where to position will be dictated by the enclosure. Most quality, reptile specific bulbs will have recommendations on the packaging or on their website. Alternatively, your reptile veterinarian can help with any questions you may have.
Ensure there is no glass or plastic between the light and the skink as in most cases, this will block out all UVA and B. Certain screens can block and reflect up to 80% of usable UV so take this into account when designing the enclosure. It is also possible to provide too much UV. If this occurs, it has been linked to eye inflammation, skin diseases and possibly, some cancers. UV bulbs made and tested specifically for reptiles should be the only bulbs used.
UVB is important to assist your skink to produce Vitamin D3 in the skin. Vitamin D is needed to absorb calcium from the diet to use for proper skeletal growth, muscle function, and the immune system. The condition, nutritional secondary hyperparathyroidism, often called metabolic bone disease (MBD), is one of the most common ailments seen in practice and is preventable through proper diet and husbandry practices.
All reptiles have a preferred optimal temperature zone (POTZ). For your blue-tongued skink, the range is 28-33 °C. A temperature gradient with a cool end of 21-26°C (70-80°F), a warm end of 28-33 °C (82-90°F), and a basking spot of 33-38°C (92-100°F) will ensure your skink has the ability to choose their preferred temperature.
A gradient is essential to prevent stress and allow thermal regulation to occur and to prevent overheating.
In some enclosures and climates, under tank heating can be used. These should always be used with a thermostat and air should be allowed to circulate around any heating element to prevent overheating and potential fires. As always, these are guidelines. It is essential to observe your skink for signs of temperature-related stress and adjust accordingly.
As mentioned, a thermostat must be used with all heating elements, and thermometers should be placed in multiple areas and checked regularly to monitor temperatures. An infrared thermometer is recommended to assess the different temperatures throughout the enclosure. Additional ventilation or extractions fans can help reduce the risk of overheating, and as mentioned, careful selection of location and provision of permanent shade areas is critical in outdoor enclosures.
Don't Forget About the Sun!
There is no better source of UVA and UVB than the sun. Allowing your Blue-tongued skink to have access to natural sunlight daily or even weekly will be beneficial.
Your skink should be supervised when taken outside, they can escape quickly, get snatched up by birds and eat things they shouldn’t. An outdoor basking enclosure can be constructed to ensure safe access to the sun. In all situations, it is important to make sure your skink has access to a hide for safety and a suitable area to escape the sun to avoid overheating.
Dietary Requirements for Blue-tongued Skinks
Blue-tongued skinks are omnivorous reptiles that eat a wide variety of vegetables and animal protein. As juveniles, half of their diet should come from insects, whereas adults should eat proportionately more plant matter. Adult, Blue-tongued skinks can be fed every one to two days, while juveniles can be fed daily. The bulk of the diet (45-60%) should consist of greens.
Feed dark, leafy greens such as mustard greens, kale, dandelion, endive, romaine, beet tops, bok choy, and collard greens. Carrots, pumpkin, squash, and zucchini can also be added and should be grated to aid in digestibility. Small amounts of fruit may be offered as an occasional treat but can lead to dental issues if fed too regularly.
Additional protein sources can be offered such as farm-raised snails, earthworms, gut-loaded crickets, black soldier fly larvae, mealworms. These protein sources should be dusted with a calcium carbonate source. The occasional frozen-thawed pinky mouse can also be offered.
A portion of the diet can have a formulated food made for lizards, but it is not recommended that this exceeds 25% of the total diet.
Can You Feed Blue-tongue Lizards Dog Food?
The use of wet dog food is controversial. Dogs and blue-tongued skinks are both omnivorous, so there the thought that these diets may be suitable for your Blue Tongue. Many have used these diets and have had healthy-appearing lizards that thrive and reproduce. Users should be cautious about the quantity of these foods fed and, if used, should only make up a small portion of the overall food intake.
It is essential to feed your skink the right proportion of food and offer the highest quality food. The practice of feeding the food source a good quality diet has been termed “gut loading“. Feed the insects the gut loading diet for 12-24 hours prior to feeding them to your skink to maximise nutrition. A mixture of veggies with a vitamin supplement is one way to achieve this.
For adults, the gut-loaded insects can then be lightly dusted 2-3 times per week with a calcium powder that does not contain Vitamin D or phosphorus and should be offered immediately after dusting. This will aid in maintaining the ideal calcium-phosphorus balance. Alternatively, a liquid calcium supplement can be administered at a prescribed dose.
It is advised to offer food in the mornings so that digestion occurs during the warmest part of the day. A multivitamin powder can be sprinkled on the vegetables every one to two weeks, but this is often unnecessary with a well-balanced diet.
Fresh, clean drinking water should be provided daily for your Blue-tongued lizard.
During the cooler months, wild, Blue-tongued skinks will often slow their metabolism down in response to the lower temperatures, shorter day length and decreased availability of food and water. Despite a more controlled environment in captivity, millions of years of instinct can still take over and cause your bluetongue to enter this slowed state.
During this period, your blue tongue may not eat, drink, defecate, or move for several weeks. They may bury themselves entirely underground; go to the darkest coolest part of the enclosure, becoming very unresponsive.
A healthy skink can safely undergo brumation, but young skinks (under 12 months old) or those with underlying disease should not be allowed to enter this state. It is recommended that your reptile veterinarian performs a physical exam prior to each brumation period.
The current recommendation for Blue-tongue skinks quarantine is a minimum of 3 months, but a 6-month quarantine period may be safer. Quarantine periods can be shortened if specific screening tests are performed. These include a physical exam, internal/external parasite checks and viral testing.
Gender Identification (Sexing)
It can be difficult to determine gender in skinks. There are many reports of using Body size and shape, head shape, pelvic width, and tail length to differentiate males from females. There is an overlap in these features, which can lead to the misidentification of gender.
Other methods reported have been probing the hemipenal or hemiclitoral fossa and eversion or “popping” of hemipenes. Both methods have risks of damaging the lizard if not performed correctly and can be misinterpreted.
Ultrasound can be used to view the gonads, and the presence of ovaries, follicles or testes is an accurate test. However, the thick scales and a large amount of air in the lung and gastrointestinal tract can impede the ultrasound waves, making this detection mode problematic.
Endoscopy, CT or MRI are other imaging modalities used, although the latter two modalities are impractical for most keepers. At this stage, there are no commercial DNA tests available to determine gender in reptiles in Australia.
Recent work using a water-soluble dye instilled into the hemipenal pockets followed by x-rays of the area has shown to be a highly accurate means of sex determination in blue tongues and is the current preferred method.
Of course, visualisation of the hemipenes confirms an individual as a male and having offspring or excretion of unfertilised yolks can be used as a means of sex identification in females.
Common Medical Conditions:
There is an extensive range of common medical conditions that we see in Blue-tongued skink lizards. Some of the conditions that we are presented with include:
- Nutritional Secondary hyperparathyroidism (Nutritional Metabolic Bone Disease)
- Skin infections
- Respiratory disease
- Dental disease
- Hemipene impaction
- Reproductive issues
- Fatty Liver (Hepatic lipidosis)
- Nidovirus (Bobtail flu)
- Overgrown nails
How Often Should Your Blue-tongued Skink Visit the Vet?
At the Unusual Pet Vets, we recommend that you get your reptiles checked every 6-12 months as they are very good at hiding illness, with symptoms often being very subtle in the early stages.
To make an appointment, contact your local Unusual Pet Vets team or book online.