New Caledonia is located east of Australia, above New Zealand. It is a geographical area consisting of a main island (Grande Terre), an island to the south (Pine Island) and some neighboring islets, an archipelago to the north (Belep and dozens of other islets) and three islands to the northeast (Loyalty Islands). In two of these four geographical areas, R. leachianus are not present (or have not yet been discovered): Belep islands (north) and Loyalty Islands. In GT and Pine Island and neighboring islets, R. leachianus are present (in addition to dozens of other species, more or less large).
Grande Terre is an island 450 km long and 50 km wide.There is only one large city, with a port and airport, while in the rest of the island there are villages and small local communities. Unfortunately, the soil is rich in minerals, so there are several (GIGANTIC) mines that devastate it. It is cut in two by a central mountain range, which divides it into two strips, one to the northeast and one to the southwest. The northern part is more humid, richer in vegetation, rainier. It is characterized by very tall trees (30 meters) and very dense rainforests. The southern part, on the other hand, is drier with lower trees, shrubs and arid stretches. R. leachianus is present both in the north and south throughout Grande Terre. The localities where they have been found are: Poindimie, Yate, Koghis, Humboldt, Nehoue, Dumbea, Goro, Mt. Dore. In reality, there are certainly more localities, but in captivity we only have these.
Pine Island is a small island with vegetation consisting of large and lush trees. Beautiful beaches, breathtaking bays, columnar pines and trees of various species make the landscape one of the most beautiful on earth: it is a paradise. R. leachianus is present on Pine Island and on many neighboring islets: Bayonnaise, Brosse, Moro, Caanawa, Nuu Ana, Nuu Ami, Duu Ana, Menore, “ L”and others still unknown. Each pure locality comes from a different island. Bloodlines derive from animals collected in the wild from 1982 to 1995, more or less. Some are more recent.
Rhacodactylus Leachianus has several synonyms, all dictated by its size, by which it is called in all the languages of the world: giant gecko, geco gigante, gekko geant. It reaches a maximum size of 40 centimeters (measured) for a maximum weight of 500 grams. It is a very stocky, heavy gecko, with huge feet full of lamellae, large claws. The tail is short and stubby. The head is large. It is at the top of the food chain, with few natural enemies (birds of prey-mice). The pure island localities (formerly Henkeli) are the ones that grow the least. They vary from 150 to 300 grams, rarely reaching them. The average length is around 24-32 cm. For the localities of Grande Terre the situation changes, with weights from 250 grams up to 500 grams. Some GTs remain rather lean but very long, such as the Poindimie, which rarely exceed 450 grams but come close to 40 cm in length. Others tend to get very thick but remain shorter, such as the Yate. They are all over 32 cm and can come close to 40. It is very difficult for an animal to exceed 450 grams, these are rare cases, very often they stop at 350-400. The size also depends on the sex of the specimen. Females are usually smaller. There are many stories of animals of 60 cm, 50 cm, but there is not a single photo that shows a gecko of more than 16 inches, or 40 cm. Depending on the place of origin (“locality” or “locale”) and the bloodline, the adult size can vary from 130 grams up to 500.
Depending on the locality of origin and the genetic line, different colorations can be found. Basically, GTs are dark, from dark brown to black, more or less banded to almost no bands. The islanders, on the other hand, have colorations from light green to dark green with even gray specimens. The base color is lighter and the white bands are much more accentuated. The bands can also be partly pink or fuchsia. Currently, there are also animals tending to yellow, red, purple. These are genetic selections or “morphs” often obtained by crossing various localities.
Pine Island: 230-300 grams, heavily patterned, dark green. The largest of the Henkeli.
Yambe X: Locality mixed with others, only males in captivity.
Several years can pass from egg hatching to reproduction, during which the animals grow more or less quickly depending on temperature, food intervals, and humidity. Initially, the GTs usually grow faster, while the islanders take longer. On the other hand, the islanders manage to become reproductive around their 3rd year of life, while the GTs do not until their 4th-5th year. Depending on how they are fed, they can grow very, very quickly, but this would require maintaining high and constant temperatures, feeding them many times a week (almost every day), and not brumating them. I do not consider it healthy to grow an animal so explosively, especially for calcium absorption and bone formation. Feeding them so often and so much can also strain their kidneys, digestive system, and liver. A well-kept animal can reach, regarding the former Henkeli, 50-70 grams in a year, 110-130 in two, and 180-200 in three. If they reach 180 in four years, it makes little difference, it is still fine. The important thing is that they do not reach it in 11 months. On the other extreme, I have seen animals declared to be 2 years old weighing 20 grams. That is not healthy either. Regarding the GTs, the growth rate is almost double: 120-150 grams in a year, 250 in two, 300-350 in three years.
The topic of food is one of the most discussed when talking about giant geckos. Some feed them only insects, some use only dehydrated food (Repashy-Pangea, etc.), and some make homemade pastes. There is no magic formula, no rule, except perhaps one: vary. R. leachianus eats practically everything from fruit to chicken, cockroaches, other geckos, small birds, eggs. They do not eat acidic fruits like oranges, grapefruits, and tangerines, but everything else is well-liked. Personally, I have found a great love for figs, at the top of the list without equal. They willingly eat papaya, banana, kiwi. They adore watermelon and melon. They also eat pears, apples, plums… They digest everything, but I do not know if they have the enzymes to digest lactose and its derivatives. The mixed fruit I use is varied, not just one type at a time, but a mix to give it a lickable consistency, not too dry. It is better if it is a little more fluid than too solid.
Regarding the humidity necessary for the health of leachianus, I can say that a room humidity of around 60% is more than fine. I tend to spray a little water twice a week, being careful that it dries quickly and does not stagnate. Ventilation is of primary importance; these are geckos that eat a lot and consequently make a lot of mess. A good air exchange is necessary. In winter, the right temperatures are between 15 and 18 degrees Celsius. In summer, a maximum of 28 degrees Celsius is recommended. Personally, I never reach them, I usually stay around 26. Temperatures above 30 degrees Celsius are lethal, especially with high humidity percentages.
We can divide the life stages of leachianus into three: baby, medium, and adult. In the first phase of its life, it should be kept in a 20x20x20 cm box. It seems like a small space, but animals of this size in the wild live in small cavities in small branches, practically never coming out to avoid being preyed upon. In captivity, they are very shy, should be touched as little as possible, and are very static. If they are not disturbed from the first week after hatching, they feed themselves independently. They stay in this space for about a year, a year and a half, until they reach 50 grams.
The second phase ranges from 50 grams to 150 grams. The best results are obtained using 30x30x40 cm boxes. In larger containers, such as 60x40x40 cm, they struggle, do not adapt well, and do not feed regularly. In this phase, growth is rapid and appetite is not lacking.
The third phase starts from 150 grams upwards. The animals are moved to 60x40x40 cm enclosures where they will remain even permanently. Obviously, a GT of “over 300gr” size should later be moved to a slightly larger place, 70x50x50 cm may be sufficient for a close-knit pair.
The terrarium suitable for a pair of adult giant geckos is at least 50x50x70h cm. The best material is expanded PVC, preferably black. Well-ventilated glass terrariums or plastic ones with appropriate modifications are also suitable. 20x20x20 cm cubic Braplast boxes are excellent for newborn babies, up to 50 grams. “Samla” Ikea plastic boxes are excellent for small growing geckos, from 50 to 150 grams. Easy to wash, they are light and indestructible. For the bottom, pine bark found cheaply at garden centers. Single geckos, whether small, medium, or large, are kept with three fingers of bark on the bottom. It maintains humidity by soaking and prevents the gecko from walking in the wet. Any excess water remains at the bottom, lower down. The bark can be colonized by woodlice (which are bought at fairs) that clean feces and debris. These need a substrate to live in and proliferate very well in the bark. A 10-15 cm diameter cork tube, obviously perforated, creates the den. Laterally, on one of the walls, I always attach 2 cup holders, one for water and one for food. Water in a 200ml glass, food in an 80ml one.
On the lid of the box, I make several rows of holes with a drill and a sharp bit or with a hot soldering iron. Terrariums must be well ventilated. Nothing kills leachianus like too much humidity and too much heat. They are geckos that live on trees in the middle of sandy islets, so after a storm the water drains quickly. They must stay dry!
To reproduce R. leachianus, you need to have a fertile male and female, well-cycled and that get along. Reproduction begins with a brumation at 15-18 degrees Celsius for 2 months. From December to February, I leave the temperatures low, with the room air conditioner set at 15 degrees. Some days it goes up, others down… but it remains low for at least two months. After this period, I raise the temperature to around 22 degrees. After a while, the first matings will be noticed. Some couples do not give problems, others will be incompatible. The incompatibility of two animals can have several causes. The first can be the refusal of the female, although ready, to mate with the male because she considers him weak. This happens when the male is small, young or weighs less than the female. A young and small male may not be as decisive as a fully adult or even old male. Another cause may be the fact that the female has retained eggs and is therefore not “in heat.” Sometimes it happens that they develop eggs during the winter if not well-cycled and that these remain inside the gecko for too long. Often they are expelled, sometimes they get stuck, cannot come out and the gecko can die. If the female is not receptive, she does not allow herself to be “mounted.”
For those who believe that leachianus are just larger ciliatus: you could not make a bigger mistake. It does not work like ciliatus: after laying eggs, they MUST mate again, otherwise egg production stops. Sometimes it happens that the female refuses the male between one laying and another, at the time of the second or third mating. I have no idea why, but it has happened more than once. Other couples, on the other hand, are very close-knit and lay eggs four, five times a year. Not all years produce in the same way, a couple that produces 8 good eggs one year can produce 2 good eggs the next year and zero the year after. Then start producing 6 good eggs the following year. Mysteries.
leachianus is a hardy animal. If kept properly in a terrarium, it is very successful, grows a lot, well, eats and does not give big problems. What not to do? When it is small, it should not be touched. I personally check all the animals once a week for 5-10 seconds, during the day, opening the tube inside which they sleep. They get used to handling easily, but it is not advisable to touch them too much until they reach 30-40 grams. They are fragile. They can stop eating. Sometimes they do, no problem, they have to feel like eating and if they do not feel like it, it is not advisable to force them. Out of 100 animals, usually none have problems feeding themselves by licking from the plastic cup. No one has ever been force-fed, no one has received “smears” of food on the snout to make them “start.” If the humidity is right, they have a shelter and a good bark bottom, they move a lot at night and find food on their own. Another thing not to do is to keep them too humid. Humidity is the enemy of these geckos, which tend to get their paws dirty in the substrate. It is not good for the delicate skin of their belly. They can contract fungi, shedding problems, rotting skin problems. Fingers can even fall off or they can have leg infections. Small ulcers that expand and bleed are frequent if the gecko remains wet. A quick weekly check gives us the possibility to notice the health of the animal and, if any pathology is present, to intervene quickly and decisively. Another problem is dehydration. It is sufficient to spray twice a week to maintain a humidity of 60% to avoid dehydration. It is important to always provide water in a cup or glass. One of the most important things to do is to administer the right dose of calcium and D3 with each meal. I have seen many animals (not mine) grow sick and crooked due to homemade diets not well supplemented with calcium. Another necessary consideration is that on the brumation of babies. It is not advisable to brumate them the first year, it is enough to lower the temperatures from 25-27 to 22 degrees Celsius for a couple of months. Not heating them is equivalent to stopping their metabolism completely and is not good. Personally, however, I brumate all my animals. Of all sizes and ages.
leachianus is a fairly peaceful gecko. If accustomed to contact with humans, it is not a biting gecko. Some have a very calm character, others (rarely) are grumpy. In general, Henkeli are rather docile, so they are recommended for those who want to touch their animal or are perhaps at their first giant. I would not recommend Poindimie, Yate or other GTs to anyone: being animals that grow a lot, they can inflict serious damage. Their head is about twice that of an adult Tokay. The teeth are small but very sharp, like knives. The defense mechanism of the leachianus is quite intuitive: first it inflates the body, inhaling air. Then it inflates the throat, and starts to emit whistles and noises. If it is in the terrarium, this is the time to approach with gloves. By bringing your hands towards the animal, it is easy for it to bite. If it does not bite, once taken in hand, it can vent by emitting moans similar to the growl-bark of a dog. Vocally it is very strong. It screams loudly and in a frightening way, it is not by chance that it is called the “devil in the trees.” It opens its mouth to bite, but if treated calmly and with respect, it stops after a while. Never squeeze or tighten it, it is the worst thing to do. It is often advisable to touch leachianus during the day. Cleaning, egg searching, and feeding operations should also be done during the day. It is better to feed shortly before twilight. At night, being fully awake, they may be more prone to wriggling and biting. With temperatures below 20 degrees Celsius, the animals are less active, calmer, while in the middle of summer they are more difficult to tame.
Leachianus is not a gecko in danger of extinction. There are critical issues related to the micro-habitats of the islands that can be destroyed by fires, sea storms, tropical storms. Fire ants have also arrived on the islets, which do not help, and mice/rats that prey on eggs and young. On Grande Terre, on the other hand, the greatest danger is constituted by man who sets fires, creates pastures by clearing land, and builds roads. The major cause of deforestation is mining: there are huge mines of ferrous metals and copper that extend as far as the eye can see. Obviously, both the extraction with bulldozers and the process to separate metals from the earth are destructive both for the mountain habitat and for the marine one. Fires are the order of the day and are enormous: hundreds of thousands of geckos die during these very extensive fires. The phenomenon of poaching is really negligible compared to these numbers, the geckos are really difficult to observe and even more difficult to capture on trees that reach 40 meters in height.
To gain knowledge about leachianus, it is advisable to buy the book “The Life of Giant Gecko.” Beautiful. Other interesting books are “mixed” books on the genus Rhacodactylus, one by Seipp and Henkel “Rhacodactylus: Biology, Natural History & Husbandry” and one by De Vosjoli “Rhacodactylus: The Complete Guide to Their Selection and Care.”
