The name of this amazing reptile contains the word Crocodile. This lizard, indeed, outwardly somewhat resembles an alligator, only of “pocket” sizes. Most of all, the similarity is found in the convex, spiny scales that nature has endowed this reptile. These unique and slightly strange reptiles have attracted zoological attention back in 1994 when the species was first described. Nevertheless, there is still a lot of unexplored. Many people are not even aware of the existence of these lizards.
Crocodile Skinks stand out among all reptiles. Their scales resemble the armor or skin of prehistoric animals. On the bony scutes of the back and on the tail of the lizards there are pointed cone-shaped keels, for which the skinks were called spiny. The head of these reptiles is triangular in shape, with well-developed cranial arches on it. Other features that distinguish Crocodile Skinks include partially fused intermaxillary bones and one parietal bone, which has a large opening for the parietal eye – the same one known as the “third eye” and found only in some reptiles.
The teeth of these lizards are pleurodont, that is, located on the inner edge of the jaw. They are about the same size, have a conical and slightly rounded shape, and seem to be slightly bent back. There are also reptiles with teeth on the pterygoid bones. The natural originality of Crocodile Skinks is manifested in the presence of skin glands on the underside of the toes, similar to the pores of the agamic lizards. And of course, the different types of Crocodile Skinks have small but noticeable differences. Males in all Skinks species are larger than females.
All Crocodile Skinks spread across the territory from Indonesia eastward through New Britain to the Solomon Islands in the Pacific Ocean. Each species in this area occupies its own plot. Say, the slender Crocodile Skinks is found in Papua New Guinea on the Admiralty or Manus Islands, and the typical Crocodile Skinks lives in the west of New Guinea, known as West Irian. Several different species are also found in the Solomon Islands. And although the climate in this area is quite diverse – there are tropical forests, and arid savannas, and even snowy mountains, Crocodile Skinks carefully choose biotopes, and in this respect, they are quite demanding. They prefer, mainly, humid forest tropics, an area near freshwater sources, where there is much different vegetation since under it ground Skinks can easily hide and find food. They are also often found on coconut plantations. However, herpetologists note that, in general, Crocodile Skinks easily adapt to new habitats, so that they take root well in captivity.
Behavior and Lifestyle
The main data on the behavior of Crocodile Skinks were obtained from observation of them in terrariums. It is known that these lizards lead a crepuscular terrestrial life, in case of danger preferring to hide in dry foliage or coconut substrate. They hunt at dusk and dawn and, in general, are rather shy creatures, so they hide most of the time.
Only the desire to swim can make Crocodile Skink leave the shelter – Crocodile Skinks are very fond of water and especially often plunge into it before molting, freezing motionless, and spending so much time. So if such a pocket crocodile lives in your terrarium, do not forget to put a shallow but spacious container of water for it, so that the Skink can comfortably fit in it.
In all other respects, Crocodile Skinks are quite sensitive. They do not tolerate cold, because of which they easily catch colds, long travel, from which they lose weight and become dehydrated, as well as active invasion of personal space, feeling which, they can begin to make sounds similar to quacking. Recognizing the painful condition of a lizard is easy. In a Skink, the orange rim of the eyes immediately turns pale. If this happens, the pet may need to be treated.
Maintenance and Care
It must be remembered that ensuring the correct housing conditions is the key to a healthy pet. If the cage is too hot or too dry, it can lead to, at best, stress or health problems, and at worst – death. In order to avoid such gross mistakes in the conditions of detention, always try to recreate the conditions of existence as close as possible to natural conditions. This applies not only to Skinks but to all terrarium animals.
The size of the terrarium for one Crocodile Skink should ideally be about a quarter of a square meter (square, with a side of 50 cm or a rectangle of 40 by 60 cm), and for a couple, the area should be increased by 50% (up to 50 by 70 cm). Like all reptiles, they need some temperature gradient inside the enclosure. The daytime temperature should be at least 23 degrees in a cold corner and no more than 28 in a warm one. At night, the temperature should not drop below 20 degrees. It is worth remembering that Crocodile Skinks requires a UV lamp. UV radiation plays a huge role in the life of daytime reptiles because it is thanks to it that the body produces vitamin D3, which is necessary for the absorption of calcium by the body. The absence of UV radiation, especially during the growth of the animal, leads to sad consequences, such as, for example, rickets. And do not forget to change the UV lamp, because, after 6-8 months of use, it practically does not carry any UV radiation.
The substrate in the terrarium can be very different. For example, orchid bark or coconut substrate is great for Skinks. You can also mix different substrates to make the soil look more natural. A piece of bark is great as a hiding place, but if you keep more than one Skink in a cage, place a few of these in case the animals don’t want to sit together. Also, take care of a humidity chamber for your pets. Simply put, it is a small closed container with a hygroscopic substrate, i.e. filler capable of keeping moisture. An example of such a filler is sphagnum moss. And as a container, a food container with a cut opening for the entrance can be suitable. An important point regarding the ventilation of the terrarium itself – try to avoid overhead ventilation, use side ventilation – one row at the top of the wall and another row at the bottom of the opposite wall – this will ensure complete ventilation of the volume, and will also allow you to maintain a high level of humidity in the terrarium for longer (75-80%).
The next important point in the correct arrangement of the terrarium is the presence of a large drinking bowl, in which the water should be changed regularly. The drinker should be large enough to fit the animals completely. With such a small size of the animal, it will not be difficult to provide this item, and the animal will appreciate your efforts, spending a long time bathing in the water, and they love it. The main thing is to change the water to clean and fresh water more often. By the way, a large drinking bowl will help to solve the problem of maintaining humidity in the terrarium.
When decorating the terrarium, be guided by the fact that the main thing for Crocodile Skink is the presence of shelters (both dry and wet) and the presence of a large drinking bowl with clean water. Everything else is not so important for them, you make the rest of the decor exclusively for yourself, for a pleasant contemplation of the beautiful animal in a beautifully designed terrarium. You can also use live plants when decorating, but you should choose them wisely – the plants should not be toxic to Skinks and should be suitable for the conditions in the terrarium, i.e. there should not be a low or high level of humidity due to the fact that the plant is uncomfortable. The conditions in the terrarium are set by Crocodile Skinks.
Crocodile Skinks find food easily where they live. In tropical thickets, there are many insects that are tasty for them: small larvae, worms, snails, slugs, crickets. Some invertebrates are also caught in the water. In captivity, it is recommended to create the most varied diet for lizards with the addition of calcium and vitamin D3.
Feeding juveniles differ from adults in that juveniles should be fed every day, and mature ones should be fed three times a week. It is also not recommended to overfeed Crocodile Skinks with various worms, as these insects contain a large percentage of fat.
The owners hardly manage to watch how the Skink eats. He prefers to do this when no one is seeing, due to his circadian rhythms – late in the evening or early in the morning. So do not be alarmed if it seems to you that the lizard is not eating anything. It is enough to pay attention to whether the amount of food that you put in decreases and everything will immediately become clear. By the way, zoologists affectionately call such secrecy of Crocodile Skinks “shyness”.
Males are usually larger than females, but females are more rounded in body shape. In addition, males have the aforementioned gray or blue pores on some of their toes. They are thought to be responsible for the release of pheromones. And females are distinguished by the presence of a convex square on the abdomen in the area of a possible navel, sometimes it is called the abdominal press. Crocodile Skinks are not particularly fertile, and they reproduce only if they like the environment. Therefore, taking care of lizards during the breeding season in captivity should be especially careful. In particular, for the normal reproduction of their own kind, they need high humidity, since the natural mating of Skinks occurs during the rainy season. And in the terrarium, you will have to constantly spray their home.
Observers of Crocodile Skinks’ behavior during the breeding season claim that the male looks after the female in a special way. Whether this happens in nature is unknown. However, in the terrarium, the male approaches the chosen one, nodding his head and widening his throat, and then begins to walk around her until the female gives a sign of favor. When mating, the male grabs the girl by the neck and wraps his tail around her tail.
Crocodile Skinks are mostly oviparous in breeding mode, but, unlike most reptiles, their clutch is limited to only one egg. True, it happens up to 6 times a year. And limited fertility is explained by the partial or complete loss of functions in some species by the left oviduct. Although, it is possible, and vice versa – the decrease in the number of eggs over time contributed to such changes. On the other hand, scientists suggest that in some species of Skinks, embryos began to develop directly in the working oviduct. But, one way or another, the females of these lizards have only one ovary. Viviparous thorny skinks are also found. For example, the species Tribolonotus schmidti, the female of which gives birth to one baby. But this feature is a rarity both in this genus and in reptiles in general. As for oviparous Skinks, their females lay one egg covered with a leathery shell. In terrariums, such eggs are placed in an incubator, however, they should be taken care from the female, since she tends to actively protect the clutch. The incubation period is 3 to 4 months. The embryo can develop normally only if there is sufficient humidity and high temperature around – 22-27 degrees.
The young do not hatch immediately but pierce the leathery shell of the egg several times so that air gets inside, and only then expands this gap and gets out. Crocodile Skinks are born very small, about 5-6 cm in size. Like adults, they differ in their peculiar behavior. If a small Skink gets scared of something, then he immediately falls and pretends to be dead, while trying to barely breathe. In this state, it is not recommended to touch babies until they get used to the presence of a person. And over time, Skinks turn into cheerful and active creatures that begin to hunt immediately after the first molt.