Red-eyed crocodile skinks (Scientific name: Tribolonotus gracilis) are an extremely shy reptile, but despite preferring a quiet life these skinks can be an absolute joy to keep in captivity. Known for the red/orange circle around their eyes and a crocodile-like scale pattern, adult croc skinks will max out at around 7-9 inches in total length and have a captive lifespan of up to 7-10 years. Don’t be alarmed when you see a juvenile red-eyed skink without the red circle as it takes time to develop.
Natural Habitat
A tropical species originally from Indonesia and Papua New Guinea, croc skinks require temperatures that range from low 70s Fahrenheit to low 80s. Humidity needs to stay above 70% for them to thrive, which can easily be achieved in captivity with a water feature within the enclosure. As a crepuscular species active mostly during dawn and dusk, croc skinks spend the majority of the daylight hours in forested areas under moist leaf litter and logs on moss and soil.
Enclosure
Like elaborate aquariums, a croc skink’s enclosure is one of the most rewarding parts of keeping these little dragons. Since they are more of a “look don’t touch” display animal, a well-scaped paludarium consisting of a fully planted, bioactive terrestrial section combined with an aquatic pool can be a wonderful addition to your home.
Size
I have been successful housing male and female pairs of croc skinks in 40 gallon breeder paludariums. For a visual paludarium build guide, please check out my video on how I created a croc skink habitat: https://www.youtube.com/watch?v=mvESW1JMO7Y. Single adult skinks can live in 20 gallon long or similar sized enclosures, but to complete a proper paludarium setup the 40 breeder size is just easier on keeper and animal to move around in. Hatchlings are better suited to more sterile tub setups in the beginning to monitor feeding and defecating activity. Once they are consistent, juvenile skinks can be moved to a larger tub, 10 gallon, or 20 gallon long enclosure.
Contents
The aquatic section of a paludarium easily keeps humidity levels over 70% with proper ventilation and also gives the animal a place to drink and submerge. A turtle filter/pump or similar should be used for low-maintenance water care. The terrestrial side should include a selection of hides, plants, leaf litter, moss, soil, and dedicated water and food bowls. I find cork bark, coconut halves, and reptile safe plants such as pothos and ferns allow the skinks to pick and choose where they want to reside.
Lighting
UVB lighting is a controversial subject for crepuscular species, but I have had success offering very low levels of UVB through the 40 gallon breeder’s screen top, measured with a UVB meter (very handy tool any keeper should look into). The Arcadia Shade Dweller (https://www.arcadiareptile.com/lighting/shadedweller/) mounted at one end of a planted enclosure is great for crepuscular species to choose to bask or seek shade among the leaves and hides. I feel if the sun is available in nature, it should be available for captive animals.
Temperature
As far as temperature gradients, I keep my skinks in one of my warmer reptile rooms so ambient temperatures average in the mid-70s and no supplemental heat is necessary. If your home is cooler most of the time, heat should be added on a case-by-case basis. UVB lamps give off a nominal amount of heat, and when placed on one end it of the enclosure offers a nice 1-3 degree temperature gradient for thermoregulation and basking options.
Handling
Frequent handling is not recommended with these guys because of their timid personalities, though I am working with gregarious individuals in an attempt to create a more personable line of captive animals. Sometimes food can be used to coax them out of their hide, however, most of the time croc skinks will either freeze and play-dead or scurry away to safety at the sight of you. If you do need to grab them they are able to drop their tails when threatened and sometimes can bite, so please exercise care when handling.
Feeding
Croc skinks are insectivores who, in the wild, use the low light of morning and evening to safely forage for a variety of worms, beetles, roaches, and crickets. In captivity skinks will often feed when offered as long as they are comfortable with their surroundings. Still, I try to feed mine in the morning before going to work, or right when I get home in the evening. A good rule of thumb for both juveniles and adults is to feed items that are smaller than the space between their eyes.
Hatchlings and juveniles do well with cut up nightcrawlers, wax worms, dubia roaches, and though I do not offer personally, crickets. Hatchlings are offered food daily, juveniles every other day. Adult skinks eat those same feeders in addition to more superworms every 2-3 days. My feeding bowls consist of plastic bottle caps for hatchlings, moving to escape proof bowls with a ledge for juvies and adults. You can choose to use these types, or more natural store bought bowl options. Since I offer my skinks UVB I do not dust with calcium + D3 every feeding, juveniles every other feeding or so, and adults about once a week. Though I up a female skink’s calcium intake when she is producing eggs.
Breeding
Sexing croc skinks is actually relatively easy compared to other reptiles. Males have grayish raised pores on the underside of the long digits on their back feet, whereas females do not. Another main difference is males have several rows of more squared scales on their lower belly than females.
A good sign of a proper habitat is breeding activity in adult pairs. Red-eyes can be kept in male and female breeding pairs, possibly 1.2, though same-sex pairs are not recommended as there is the potential for territorial behavior. As with any breeding endeavor, always start with mature/large enough animals who are properly fed and housed. Females need calcium for egg production so a diet poor in quality feeders without any UVB can be a recipe for disaster.
In the wild breeding is triggered by the wet season from December to around March, and can be triggered the same way at any time in captivity by upping the humidity. Once mated, females lay one egg about every 6 weeks or so over the duration of the season, or about 4 months.
Croc skinks are fairly unique among reptiles because they will actually care for their young once hatched. Some keepers prefer nest incubation within the enclosure, some prefer removing the egg to incubate on a separate hatching medium. From experience, I have had good results with both incubation methods, so I would recommend experimenting for yourself to see which you prefer. I will mention though that if your enclosure is not spot-on, there is a larger possibility of egg failure when left to the elements of mold, fluctuating temperatures, and too high/little moisture within the enclosure.
So you’ve got an egg, have chosen your method of incubation, now what? Candle the eggs for veins to make sure it is actually fertile. Then you should wait about 60-90 days, and BOOM, baby croc skink! I like to incubate at lower temperatures for a longer period and will start keeping a closer eye on the eggs around 70 days. The eggs will grow significantly from their initial laid size. Watch out for sweating. While drops on the egg late in the term do not necessarily mean the egg has failed, early sweating can indicate issues with the shell quality and troubles within.
Is a red-eyed crocodile skink for you?
Now that I’ve outlined some basic information and care for these intriguing mini-dragons, you should have a better idea about whether or not a croc skink is the right fit for you. Red-eyes can be incredibly rewarding to observe in a captive habitat, though if you are looking for an animal to interact with you might look beyond these shy little skinks.
