Crested geckos are a crepuscular / nocturnal, semi-arboreal species originating from the tropical forests and scrublands of New Caledonia. Although they were actually thought extinct until their rediscovery in 1994, they are now probably the second most commonly kept gecko after the leopard gecko. Their popularity looks set to increase due their simple husbandry requirements, general tolerance of handling and the availability of an increasing number of colour and pattern forms or 'morphs'.
Appearance
Overall the crested gecko has a slender to medium build, with a broad, flattened, triangular head and long, slender tail. A row of spines or 'crests' run from the inside of each eye, along the head and back to the base of the tail. The large, prominent eyes are not lidded, but instead retract slightly into the head when the gecko is resting, at which time the crests above the eyes and head appear to 'droop'; when awake, the geckos will periodically clean the eye using their long tongue. The stocky limbs of crested geckos terminate in broad toes, which are covered on the underside in the lamellae that the gecko uses for adhering to surfaces while climbing. A further set of lamellae can be found on the spatulate tip of the geckos long, prehensile tail. Although wild-type crested geckos tend to be brown in colour and with little or no patterning, selective breeding has produced a range of different colours (including yellow, red, orange, cream and olive) and patterns or 'morphs' (such as bi-colours, tigers, brindles, flames, harlequins and pinstripes) among captive bred specimens. More comprehensive information on these variations can be found on the Rhac Shack website.
Image top-left shows an adult female orange extreme harlequin crested gecko. Note the variation in colour between the dorsal region between the crests and upper part of the flanks. The mottling on the lower part of the flanks and legs is characteristic of this morph. A sub-adult male partial pinstripe crested gecko is shown in the top right photograph. The fact that the crests on this gecko are paler than its overall dorsal region is what makes it a 'pinstripe', though as this pattern is broken it is only a partial, rather than a full pinner. If the colouring of the crests is darker than the rest of the gecko, as shown in the image of the sub-adult male gecko shown bottom left, this constitutes a reverse pinstripe morph. The crests on the geckos shown in the bottom right image are particularly well developed, as are the portholes on this specimen; the small area of pale, raised scales on its flanks.
When a crested gecko is awake and alert, the crests immediately above the eye and along the side of the head are held erect, as shown in the left hand image above. The image to the right shows the retracted eyes and drooping crests typical of a sleeping crested gecko.
Size
Adult crested geckos can attain a total length, including tail, of approximately 200mm, with the normal weight range considered to be anything from 40g to 60g.
Sexing
Males can be distinguish by the presence of both a large hemipenile bulge and a double row of pre-anal pores. Sexing these geckos can be notoriously difficult when they are juveniles, as the age at which pre-anal pores and a hemipenile bulge develop is highly variable; in some males pores may be apparent from a few months of age, whereas others may be considerably older. As males are territorial and will fight, potentially causing severe injuries, I prefer to house crested geckos separately until their sex can be confirmed.
The photograph on the top left shows a A) the pre-anal pores and B) the hemipenile bulge of an adult male crested gecko; a lateral view of the hemipenile bulge is shown in the image bottom right. For comparison, the adult female shown in the two right hand photographs shows an absence of these features.
Care requirements
The husbandry of crested geckos is relatively straightforward and their care requirements are comparatively undemanding.
Housing
Crested geckos, like other species, are solitary animals and only tolerate the presence of another gecko. If two or more females, male: female pairs or breeding groups of one male to multiple females are to be housed together, then care must be taken to ensure that the geckos are of approximately the same size / weight to minimise the risk of bullying / fighting.
Enclosure
Crested geckos are a semi-arboreal species and should therefore be housed in enclosures which provide them with plenty of height for climbing. Between one and three geckos can be housed in a vivarium measuring 45cm x 45cm x 60cm as long as plenty of hiding spaces are provided. As this species requires relatively high levels of humidity, many keepers favour glass enclosures over wooden ones, which are prone to warping. The glass vivaria produced by Exo Terra are perfect for this species.
Temperature
It is frequently stated in care sheets that it is possible to keep crested geckos without additional heating as long as the ambient daytime temperature of the room in which they are kept lies in a range between 21°C and 27°C (70°F and 80°F). However, even when the ambient room temperature is within the desired range, I have found that it can sometimes be difficult to create a suitable temperature gradient within the vivaria to enable the geckos to thermoregulate properly and have therefore recently started using incandescent light bulbs to create a basking spot for all of my Rhacodactylus sp geckos, including the R. ciliatus. The bulbs are housed in canopies placed above the vivaria and, as always with all artificial heat sources, are controlled by suitable thermostats (for personal preference I use Habistat dimmer stats). Using this technique, I have been able to produce a thermal gradient of between 27C (80F) directly under the basking spot and 21C (70F) at the base of the vivarium. Since introducing the basking spots, I have noticed a positive change in the behaviour of my geckos: overall, they are considerably more active and there has been a noticeable improvement in their (already good) appetites.
Humidity
These geckos require relatively high levels of humidity, with the ideal range being between 55% and 80%. Their enclosures should therefore be sprayed with water at least once a day to achieve this. I have found that, if the temperature gradient described above is maintained in the enclosure, then thoroughly misting the vivarium so that all foliage is dripping wet each evening will result in humidity of approximately 80%; this will then fall over the course of the next 24 hours, until a minimum if between 55% and 60% is reached immediately before the enclosure is sprayed once again.
Lighting
As long as crested geckos have access to sufficient natural light from a window to enable them to establish a day-night cycle, then artificial lighting is not absolutely essential. However, I have found that using an incandescent bulb to create a basking spot (see temperature) and also offering UVB light has had a beneficial effect on my geckos health..
Substrate
I've found that eco earth works well as a substrate for this species, as it maintains the high levels of humidity they require. However, kitchen towel can also be used, especially for new acquisitions in order to monitor their eating / defecation or for sick animals as it is easier to maintain the high levels of hygiene that these animals require.
Decor
Being semi-arboreal, crested geckos require decor that allows them ample opportunities for climbing. It is therefore essential to provide a range of cork branches, pieces of mopani wood and / or vines etc. Additionally, they require plenty of either real or fake foliage, as they tend to hide away among leaves and branches, especially during the day when they will secrete themselves away to sleep. Although they seem to make minimal use of hides, I've found that a few pieces of cork tube placed in the vivaria will afford them an opportunity to hide should they wish to.
.JPG "Example of a <em>Rhacodactylus sp</em> gecko vivarium")
.JPG "Further example of a <em>Rhacodactylus sp</em> gecko vivarium")
The above images show examples of the vivaria I use to house geckos of the genus Rhacodactylus.
Feeding
Crested geckos are omnivores, whose diet in the wild consists of a variety of fruit, bugs and any smaller animals that they can find. In an attempt to replicate their natural diet, I offer my crested geckos a wide variety of fruit, with lightly puréed or chopped melon, mango, kiwi fruit, fig and cherries all proving particularly popular with the Rhacodactylus sp geckos. However, due to their high acidity, citrus fruits and pineapple should be avoided. Although commonly offered by some keepers, banana has an extremely poor calcium: phosphorus ratio and can lead to health issues in the form of calcium metabolism problems. For this reason, I do not offer banana to any of my geckos. The second major component of the diet of my crested geckos is a variety of feeder insects, including crickets, locusts and dubia roaches, all of which are eaten enthusiastically. As invertebrates form a component of the natural diet of these geckos in the wild, I do not endorse the sadly all too frequently repeated advice that it is possible to maintain a crestie simply by feeding it fruit or CGD, especially as cresties reared solely on CGD as hatchlings / juveniles often display a much slower growth rate than comparable animals reared on a mixed diet. As always, feeders are gutloaded for at least 24 hours and are coated in a sprinkling of calcium before being offered to the geckos. Many keepers use proprietary Crested Gecko Diets (CGD), which are advertised as having been developed especially to provide these geckos with the nutrients that they require. Although, I have used both the Repashy diet, which can be imported from Pangea Reptiles in the USA, and Clark's Diet, which can be bought in the UK from Clark's Gecko Diet, in the past with some success, I now give CGD only sporadically to my animals. Not only does this enable me to offer my geckos a diet that more closely replicates their natural diet, but it also enables me to tailor supplementation to the needs of an individual gecko with, for example, juveniles or gravid females being given more calcium / vitamin D3 (to reflect their enhanced need for this mineral / vitamin for bone growth and egg production respectively) than an adult male.
Water
Crested geckos frequently drink by licking at the water that lands on foliage or glass when their vivaria is sprayed; it is therefore crucial that only fresh, clean water should be used for misting and that the vivarium should be sprayed every day. Although some keepers rely entirely on such daily misting sessions to provide water for their crested geckos, I have, occasionally, observed mine to supplement their water intake between mistings by drinking from a bowl. I therefore also provide small bowls of fresh water in my crestie vivs.
Supplements
If CGD is used as a staple, then most of the nutritional requirements of a crested gecko will be met, as it contains all of the vitamins and minerals that they require. However, if feeder insects are also offered, then these should dusted with pure calcium powder; it is not necessary to dust with a calcium balancer containing vitamin D3, as CGD already contains this vitamin.
Hatchling / juvenile care
The care required for hatchling and juvenile crested geckos is almost identical to that of adults, although there are a few differences. Young geckos appear to feel more secure in smaller enclosures; it can therefore be better to house them in either a tall faunarium or small vivarium (30cm x 30cm x 30cm for hatchlings or 30cm x 30cm x 45cm for slightly older animals). I have found that screening the sides of the faunarium / vivarium entirely with foliage enhances this feeling of security for young geckos and enables them to settle in to their new home more rapidly. I prefer to use kitchen towel as a substrate for young cresties, as they eat such a small amount of CGD that it may be impossible to distinguish whether they have actually touched the food in their bowl or not. Rather than monitoring their actual food intake, it is therefore easier to check for droppings, which are more readily apparent on kitchen towel than on eco earth.
The above photograph shows a young juvenile crested geckos at four months old, at which time she measured about 100mm in length and weighed approximately 3g.
Further readingBooks
de Vosjoli, P., Fast, F. & Repashy, A., 2003. Rhacodactylus: the Complete Guide to their Selection and Care. Vista: Advanced Visions Inc.
Websites
Although abundant information on crested gecko care is available online, some of it is, unfortunately, of dubious quality. Some of the best information can be found on the following sites:
The Rhac Shack website
The Treasure Crest website
