Red-Eyed Crocodile Skink (Tribolonotus gracilis)
Welcome to the ReptiFiles Red-Eyed Crocodile Skink Care Sheet! This care sheet was written by a professional reptile husbandry specialist, compiled based on reputable sources such as scientific research papers, natural history data, and the experiences of longtime keepers and breeders of this species. You can find a list of these sources at the bottom of this page.
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Red-eyed crocodile skinks (Tribolonotus gracilis) are a nocturnal, insectivorous type of semi-fossorial lizard native to New Guinea. They prefer tropical forest for habitat, but have adapted to living on coconut plantations as a result of deforestation. They can be found under forest debris, usually near a body of water.
Red-eyed crocodile skinks are approximately 6-8″ / 16-20cm long. Coloring is dark brown, gray, or black, with brown-black eyes each rimmed with orange. They have a large triangular head with a small snout and large eyes, as well as a stout body. Aside from the orange markings around their eyes, their most identifying characteristic is the rows of backward-curving spikes down their back and tubercles on their sides, giving them a very dragon-like appearance.
Red-eyed crocodile skinks are very shy and make better display animals than a pet you can handle or even watch all the time. But if you appreciate them for what they are and pay attention to providing high-quality red-eyed crocodile skink care, you may expect your pet to enjoy a lifespan of up to 10 years.
Red-Eyed Crocodile Skink Shopping List
These are products I personally recommend for setting up a functional red-eyed crocodile skink terrarium. Some of the links in this care sheet are paid links — if you’d like to know why ReptiFiles uses paid links, visit this page.
- Front-opening 24”L x 18”W x 18”H terrarium, or larger
- 50w Zoo Med Repti Basking Spot bulb
- 5.5″ Fluker’s Dimmable Repta-Clamp Lamp
- Arcadia ShadeDweller UVB kit
- Zilla 24/7 Digital Power Center
- Zoo Med Digital Thermometer/Hygrometer Combo, x2
- Exo Terra Mister
- Zoo Med Eco Earth, 15+ quarts
- Leaf litter
- Hides/caves, x2
- Environmental enrichment
- Food and water dishes
- Repashy Calcium Plus LoD supplement
Red-Eyed Crocodile Skink Enclosure Size
Red-eyed crocodile skinks need an enclosure that is large enough to give them adequate opportunity to explore, hunt, and generally exercise natural behaviors. Considering that a red-eyed crocodile skink can grow up to 8″/20cm long and they generally need a large than usual area of water, the minimum recommended enclosure size for housing a single red-eyed crocodile skink is 24”L x 18”W x 18”H / 60 x 45 x 45cm or similar. However, larger is always better!
Here are some enclosures that are appropriate for housing crocodile skinks:
- Zen Habitats 2’x2’x2′ PVC Panel Reptile Enclosure
- Carolina Custom Cages Terrarium, Medium 24Lx18Dx18H
- REPTI ZOO Reptile Terrarium, 24″ x 18″ x 18″
- Exo Terra Medium/Wide Natural Terrarium (24” x 18” x 18”)
- Carolina Custom Cages Terrarium, Large 36Lx18Dx18H
- REPTI ZOO Reptile Terrarium 36″ x 18″ x 18″
- Exo Terra Large/Wide Natural Terrarium (36” x 18” x 18”)
Can multiple red-eyed crocodile skinks be housed in the same enclosure?
No. Although they can be kept together for breeding, if you just want to keep yours as a pet, it’s best to house them singly.
Lighting & UVB for Red-Eyed Crocodile Skinks
Red-eyed crocodile skinks are nocturnal, which means that they are primarily active at night. However, they still need a light on during the day to help regulate their day/night cycle. Lights should be left on for 12 hours/day.
Because they are nocturnal, technically red-eyed crocodile skinks can survive without UVB lighting as long as they get plenty of supplemented vitamin D3. However, you are still going to get the best results from using UVB lighting rather than relying on supplements.
UVB lighting can be tricky, because in order to get the right strength of UVB (measured by UV Index, or UVI), distance must be considered. As a rough estimate, to provide appropriate UVB to a red-eyed crocodile skink in an 18” tall enclosure, you will need one of the following:
- Arcadia T5 SO ShadeDweller kit — 8-10″ / 20-25cm
- Zoo Med T5 HO Reptisun 5.0 + VE T5 HO Fixture — 11-14″ / 28-35cm
- Arcadia ProT5 Kit with Forest 6% bulb — 11-14″ / 28-35cm
The recommended distances listed above are to be measured from the skink’s back to the UVB lamp. The bulb itself should be roughly 1/2 of the enclosure’s length, no more than 2/3. UVB bulbs must be replaced every 12 months in order to remain effective.
(These recommendations are approximations. It is strongly recommended to use a Solarmeter 6.5 to determine the best placement to achieve a UVI of 1.0-2.0 in the basking area at the top of the enclosure.)
Red-Eyed Crocodile Skink Temperature Requirements
Humans are warm-blooded, which means that our body temperature is automatically regulated. Red-eyed crocodile skinks, however, are cold-blooded, and they need to move between areas of different temperatures in order to regulate their body temperature. In the wild, crocodile skinks generally warm up by resting inside a warm burrow or under a sun-warmed piece of fallen wood. In captivity, sunlight can be replicated with a white heat lamp.
- Warm hide temperature: 80-82°F (27-28°C)
- Cool zone temperature: 75-78°F (24-26°C)
- Nighttime temperature: 72-75°F (22-24°C)
You will need one or two ~50w heat bulbs for basking, such as the Zoo Med Repti Basking Spot bulb in a dimmable dome lamp such as the Fluker’s 5.5″ Dimmable Clamp Lamp. This wattage should be plenty, but results will vary based on your room temperature. If you notice that the warm hide is too warm, dial down the heat down with a lamp dimmer or switch to a lower wattage bulb. If your basking area is too cool, you will need a higher wattage bulb.
The warm hide should be placed directly under the heat lamp, with the lamp placed on the extreme right or left of the setup.
To track warm hide temperature, use a digital probe thermometer, with the probe placed inside the warm hide. Alternatively, you can use a proportional thermostat such as the Herpstat 1 to automatically maintain the warm hide temperature. Most reptile-brand digital probe thermometers function well.
If the nighttime temperatures in your home are lower than the temperatures needed for your skink, you will need a lightless heat source for nighttime. I recommend a low-wattage ceramic heat emitter connected to a lamp dimmer or on/off thermostat for the job.
Note: In order to use ceramic heat emitters safely, a wire lamp fixture must be used, not a dome.
Red-Eyed Crocodile Skink Humidity Requirements
Red-eyed crocodile skinks are very sensitive to dehydration. Keep humidity levels around 70-80% during the day, and higher (80-100%) at night. Ambient humidity should be tracked via digital probe hygrometer with the probe placed in the middle of the setup.
To raise the humidity in your enclosure, you can use a pressure sprayer like the Exo Terra Mister to mist the habitat every evening and morning, as well as possibly in the middle of the day. Alternatively you can install a Mistking automatic misting system. The enclosure should be well ventilated enough to dry out a bit between mistings.
It’s good practice to use a reptile humidifier/fogger at night to help maintain high nightly humidity levels. Make sure to use reverse-osmosis or distilled water, and thoroughly clean out and sanitize the humidifier with veterinary-grade disinfectant like Rescue or F10SC weekly to prevent illness. For optimal results, connect your fogger to a humidistat such as the Inkbird brand.
Red-Eyed Crocodile Skink Substrate Options
Substrate is an important part of a red-eyed crocodile skink terrarium. It helps maintain humidity and gives them something to dig around in, decreasing overall stress. It’s best to use a moisture-retentive substrate that is similar to the soil in a crocodile skink’s natural habitat. Here are some reliable options:
- DIY tropical mix: 60% organic topsoil, 40% coconut fiber
- Zoo Med Reptisoil
- Zoo Med Eco Earth
- Exo Terra Plantation Soil
- The Bio Dude Terra Fauna bioactive kit
Only 2-4″ / 5-10cm should be needed, unless you are planting live plants directly into the substrate. Then add a generous layer of leaf litter on top.
Feces and urates should be removed daily, and contaminated substrate should be scooped out and replaced. Substrate should be completely replaced once every 3-4 months, depending on your needs.
Decorating Your Red-Eyed Crocodile Skink Terrarium
Decorations play a vital role in your skink’s enclosure as environmental enrichment. Enrichment items encourage exercise, stimulate your pet’s natural instincts, and help promote overall wellbeing. And, of course, they make the enclosure look nicer!
Here are some ideas to get you started:
- cork hollows
- cork flats
- extra hides
- nontoxic live plants
Arrange these items in a way that encourages your skink to climb and explore, offers plenty of shelter, and creates areas of both light and shade.
Feeding Your Red-Eyed Crocodile Skink
Red-eyed crocodile skinks are insectivores, which means that they need a varied diet of insects to get the right nutrition. Juvenile crocodile skinks should be fed daily, and full-grown adults should be fed every other day. Offer as many insects as the lizard is capable of eating in a 5-minute period, with each feeder being around half the size of than the animal’s head.
Best feeder insects for red-eyed crocodile skinks: crickets, dubia roaches, discoid roaches, mealworms, superworms, hornworms, silkworms, black soldier fly larvae, earthworms, canned snails
The key to providing a healthy, balanced diet for your pet is VARIETY. Provide as varied of a diet as you possibly can, and you will be rewarded with a healthier pet that always looks forward to mealtime.
Feeder insects need to be “dusted” with a light coating of calcium powder before every feeding to balance their calcium-phosphorus ratio, and adding a multivitamin to the routine helps prevent deficiencies from developing.
There are many options, but Repashy CalciumPlus LoD is a solid all-in-one supplement for getting started. For best results, use as directed by the label.
Although your skink will likely get drinking water from routine mistings, it’s best to always keep a bowl of clean water available. This bowl should be scrubbed out with veterinary disinfectant such as Rescue or F10SC weekly for good hygiene.
Handling Your Red-Eyed Crocodile Skink
Red-eyed crocodile skinks are more of a look-but-don’t-touch display animal rather than a pet that you can handle regularly. While it’s entertaining to hear them vocalize when grabbed, this stresses them out, and they may even play dead or drop their tail.
If you want to interact with your pet crocodile skink, you can build trust by offering insects or treats via soft-tipped feeding tongs. However, wait at least 2 weeks for the skink to settle into its new home before trying to introduce yourself.
Baines, F. M., Chattell, J., Dale, J., Garrick, D., Gill, I., Goetz, M., Skelton, T., & Swatman, M. (2016). How much UVB does my reptile need? The UV-Tool, a guide to the selection of UV lighting for reptiles and amphibians in captivity. Journal of Zoo and Aquarium Research, 1, 56. https://doi.org/10.19227/jzar.v4i1.150
Crepuscular Species. (n.d.). Arcadia Reptile. Retrieved January 10, 2022, from https://www.arcadiareptile.com/lighting/crepuscular-species/
Hartdegen, R. W., Russell, M. J., & Young, B. (2001). VOCALIZATION OF THE CROCODILE SKINK, TRIBOLONOTUS GRACILIS (DE ROOY, 1909), AND EVIDENCE OF PARENTAL CARE. Contemporary Herpetology, 1–6. https://doi.org/10.17161/ch.vi1.11956
Red eyed Crocodile Skink Care. (n.d.). CHICAGO EXOTICS ANIMAL HOSPITAL. Retrieved January 17, 2022, from http://www.exoticpetvet.com/red-eyed-crocodile-skink-care.html
Tribolonotus gracilis. (n.d.). The Reptile Database. Retrieved January 17, 2022, from https://reptile-database.reptarium.cz/species?genus=Tribolonotus&species=gracilis
Wheeler, W. (2017, November 3). Red-Eyed Crocodile Skink Care And Information. Reptiles Magazine. https://www.reptilesmagazine.com/red-eyed-crocodile-skink-care-and-information/
The ReptiFiles Red-Eyed Crocodile Skink Care Sheet is a simplified care summary, not a full ReptiFiles care guide. While I have done my best to ensure that the information contained is accurate, due to time constraints, the research behind ReptiFiles care sheets is not as thorough as the research involved with my full-length care guides. I strongly encourage readers to do their own research from high-quality, reputable sources outside of just this care sheet as part of preparing for your new pet reptile.