Red-eyed crocodile skinks (Tribolonotus gracilis) are a lizard native to Papua New Guinea. They are popular for the spiny appearance that makes them look similar to a tiny crocodile.
These lizards are slowly becoming more common in the pet trade as more breeders take up the species.
If you are interested in owning one, you may be wondering:
How big is a red-eyed crocodile skink?
On average, an adult red-eyed crocodile skink is 6-8 inches long. Half of that length is their tail.
For a complete guide to enclosure setup, feeding, daily care and breeding,
check out my Red Eyed Crocodile Skink Care Sheet
Red-eyed crocodile skinks tend to hatch out at only 1.5-2.5 inches long counting their tails. It takes about two years for them to reach their full size.
They become sexually mature at 3-4 years for a male and 4-5 for a female. At full size, the skink will be 6-8 inches long.
They are around 3-4 inches from the tip of the snout to the vent. While the species can drop their tails, the tail will grow back if the animal is healthy.
They can be squirmy and typically do not warm up to handling very much, so it is hard to measure them. Juveniles will look like adults very quickly.
Like all reptiles, crocodile skinks can suffer from calcium problems if you do not supplement them appropriately.
If you do not vary the diet or do not supplement them with calcium and a multivitamin, they are at risk of serious bone defects.
You should never see any waviness or curving to the tail and other limbs. Most signs of calcium deficiencies are pretty minor at first and they can be as small as the bones of the tail starting to curve improperly.
This is a sign your skink needs emergency calcium. Make sure you visit your vet to ensure you dose this properly. Bone deformities can also be caused by poor husbandry.
Make sure you double-check all of the temperatures and the humidity. Remember that red-eyed crocodile skinks are very prone to dehydration if they do not have a water feature.
Make sure your skink has access to at least a large water dish that can fully cover its body. If you have a breeding pair, both animals should fit at the same time to help reduce competition.
A healthy adult red-eyed crocodile skink can be between 36 and 45 grams, Hatchlings typically weigh 1-2 grams fresh out of the egg, but they do put on weight quickly once they are established.
It is easy to allow the species to get too fat since many of the insects that they will take consistently are also high in fat.
Generally speaking, a healthy crocodile skink seems fairly slim. Their specific name gracilis refers to their comparatively slim and compact bodies.
It can be a bit hard to notice when a crocodile skink is too thin since they are so small. Generally, look for a thin tail compared to images of wild animals and a prominent spine or ribs.
This can be hard to notice thanks to their unique scales, but the difference can be noticed. A fat crocodile skink will have noticeable fat deposits and rolls. The tail may be unusually thick.
If you feel your adult skink is getting fat, either space out the feedings or offer prey with less fat. Do not try to adjust the diet of a juvenile skink since they need the energy to grow.
Red-eyed crocodile skinks have very little to differentiate the sexes. Males and females do overlap in length and weight. The easiest way to tell is to check the hind feet.
If you count the toes from the innermost toe, the third and fourth toes in males have enlarged scales that can be used to tell them apart.
Males in the wild likely compete to breed, so males need to be housed either alone or with a single female they get along with.
Red-eyed crocodile skinks are unusual because of their social habits. Males are solitary, but adult females care for their young and form a social group with their juvenile offspring.
Fresh hatchlings are typically only a quarter of the length of an adult at under 2 inches and will weigh much less. The mother typically cares for the young at least until the next egg she lays hatches.
This tends to take around 6-8 weeks. It isn’t unusual to see hatchlings clinging to the back of their mothers.
Hatchlings have steady growth and tend to look a bit thin compared to adults, but they do start getting their slim adult proportions by two years of age.
If you choose to breed your crocodile skinks, the babies need to be moved to their own enclosure by a year old. While the parents will tolerate their juvenile offspring, older skinks may fight.
Always have a separate enclosure ready to go if you are housing animals together in case they need to be separated for any reason.
Crocodile skinks are fairly small lizards, but they actually need a somewhat large enclosure for their size. This is because about a third of their floor space will need to be taken up by a water feature.
Generally, this species needs more space filled with plenty of clutter and a deep substrate to be happy. If you have any questions or comments, please leave them below.