There is a great deal of suggestion that Crested geckos (R. ciliatus) are an easy to keep species. Much of this speculation undoubtedly arises from their temperature requirements (which we shall go into in some detail later). Here at GlasgowGecko we are a little hesitant to suggest this species to beginner keepers, as we feel they really are less hardy in captivity than many other keepers would have us believe, however with care, attention and some focused research, they can be a truly rewarding pet.

Housing

You will find many estimates of 'minimum' vivarium size requirements for this species, and undoubtedly many justifications for these estimates. We personally believe that space utilization is the most important part of housing Crested geckos. We house our breeding adults singularly in custom built glass vivarium's (dimensions 45cm x 45cm x 45cm). Ventilation is provided by a fine mesh panel which covers half of a single wall. With this basic structure in place there are several considerations:

- Humidity: Our main focus with humidity is less based on an absolute figure, and more based on a spraying routine. We spray our animals once in an evening with enough water to dampen the substrate. It is important that you do not over spay, the substrate should have dried by the following morning. We keep our Crested geckos a little drier than some other keepers will suggest, because keeping the substrate too wet can lead to further medical, and habitat issues.

- Decor: Dense cover (made of either live or plastic/ silk plants) is essential for this species. They are by nature shy animals, and will spend much of their time hiding. For the animals to feel secure they must be able to find suitable recesses for this. Cork bark pieces, and vines of various shapes and sizes can be employed for climbing. The addition of features like this will increase the usable surface area of the vivarium, effectively giving the animal more space in which to move. One point to think about when kiting out your vivarium is that live plants will allow you to maintain humidity better than the non-live equivalents, however effective lighting to keep these plants alive can be difficult to achieve.

Temperature, heating, and lighting

Although it has been well documented that many nocturnal species thermoregulate diurnally, and that efficient thermoregulation increases growth rate in nocturnal lizards. Many captive reptile keepers appear to maintain their animals at artificially low temperatures (which often correspond with apparent nocturnal active temperatures), without correct diurnal thermal gradients. This could be effectively reducing growth rate, and affecting many other physiological and behavioural traits. One particularly poignant example of this is the Crested gecko (Rhacodactylus ciliatus), which is typically maintained at 75˚f (23˚C) often referred too as “room temperature”, without the use of an external heat source (thus essentially providing a constant single temperature). The critical assumption here is that 75˚f is the thermal optimum for this species and that this temperature is sufficient for all physical processes, which may not be fully accurate.

The results of temperature preference experiments suggest that (Tp) for this species (based on n=26) is 86˚f (30˚C). While this is toward the top end of the ‘natural’ temperature range of the species, it is not uncommon for Tp to be higher in captive situations than in the ‘nature’. This temperature is also above what some keepers refer to as a ‘critical’ temperature, at which mortality rate increases, although I have seen no evidence of this.

The effects of temperature on growth rate in two independent groups (both n=26) was tested (group 1 given the opportunity to thermoregulate diurnally, with a temperature gradient between 70-86˚f and a night temperature of 70˚f; and the second with a constant temperature across the enclosure of 75˚f) with the following results:

Figure 1: Mean body mass over time in captive R. ciliatus raised from hatching under two separate thermal conditions. Circles represent mean body mass of geckos allowed to thermoregulate at diurnal temperatures. Squares represent mean body mass of those maintained at constant nocturnal temperatures. Bars represent standard error.

 

Geckos maintained at ‘nocturnal’ temperature (75˚f) grew at a rate of 0.047g/day, while geckos allowed to thermoregulate grew at 0.058g/day. These animals were maintained on a diet consisting solely appropriately sized crickets, and number of consumed prey items was higher in the thermoregulating group.

These results are perhaps unsurprising, but underline the benefits of a diurnal thermal gradient for not only this species, but many other nocturnal species.

Based on these results, we cannot stress strongly enough the need for an appropriate temperature gradient for Crested geckos in captivity, and this necessitates the use of an external heat source, regardless of your rooms ambient temperatures. Without an appropriate gradient (and associated ‘basking’ temperature) then you will negatively impact the growth, and health of your animals.

These results (and others more conclusively demonstrating the need for an appropriate temperature gradient) are currently ‘in press’ and will be available to the wider community in the near future. In the mean time, if you want more details, please don’t hesitate to contact us.

Lighting can also be a controversial subject between Crested gecko keepers. It is generally accepted that a photo period of 12 hours should be maintained for between 8-10 months of the year. During the winter months a reduction to between 8-10 hours sunlight, associated with a slight cooling of the temperature to between 65 - 70 F can act as a natural cooling in preparation for the breeding season.

Many keepers we suggest it is unnecessary to provide UVB lighting for Crested geckos due to their nocturnal nature, however we would disagree with this for several reasons:

1) Although Crested geckos are nocturnal, short periods of crepuscular activity, along with exposure to direct and indirect sunlight while inactive during the day time in the wild allow the benefits of vitamin D3 production.

2) Crested geckos are very susceptible to MBD (See article in 'In Press' section), and so self regulation of vitamin D3 intake is more appropriate in our opinion than manual supplementation.

It is for this reason we suggest using a 2% UVB light for a period of at least 2 hours a day.

Diet and Feeding

Perhaps the most discussed topic between Crested gecko keepers is diet. While primarily insectivorous, they will also eat a variety of blended fruits, or more correctly they will eat a variety of over ripe to rotting fruit. MAny of you will also know that there is a specially formulated diet for crested geckos which claims to offer a completely balanced diet, including all trace elements that your gecko needs. Below are some possible diet suggestions:

1. Crested gecko formula diet (CGD): This diet, a mixture of all the vital ingredients that Crested geckos need, come packaged as a powder that you add to water to make a paste (for further instructions read packet). It comes in a variety of flavors, and has some good reviews from breeders and keepers that use it. You may find it difficult to persuade your gecko to eat it however, but persistence is the key here. Many keepers advocate using it in conjunction with blended fruit (something Crested geckos seem to take too instantly) and then decreasing the fruit content gradually until the gecko will eat just the paste.

At GlasgowGecko we have mixed feelings about a diet of just CGD . Animals fed on this diet have much reduced growth rates, which in our opinion is mainly due to the vastly reduced volume of food they are consuming when compared directly to those fed on other diets.

One thing that it is important to note here, IF you feed a diet comprised solely of CGD, you do not have to add further supplements to it. One caveat to this is for breeding females, when supplying a bowl of calcium carbonate in the vivarium is suggested.

2. CGD & Insects: Many keepers will tell you that feeding Insects to Crested geckos will stimulate their feeding and hunting response, which is not only nice to see but also enriching for the animals.

For advice on which insects to choose, and also how to Gut-load them appropriately please read our article on Insectivorous reptile nutrition. Size of feeder insects is also important, with a good general rule being that 'they should be no bigger than the distance between the animals eyes (however many can and do take insects far bigger than this, but problems can arise from this practice).

If opting for this method of feeding your animals we would suggest that you feed the CGD 2-3 times a week, by leaving a small bowl in the vivarium. It will dry up pretty quickly so you can remove it, and replace it every couple of days. We would then also recommend feeding appropriately gut-loaded and supplemented insects 2-3 times a week.

3. Custom blended fruit mixes and insects: The third method is only really aimed at more experienced keepers, as it requires a good knowledge of dietry requirements and a profound understanding of the health of each animal. For this reason I am not going to go into it in much depth here. However if you do have any questions please feel free to send us an email with any questions you have.

Handling

Handling proves something of a debate here at GlasgowGecko. Although some Crested geckos will tolerate handling, many will not and it can prove to be a stressful ordeal. We would urge you to consider your actions with regard to handling very carefully especially with hatchling and juvenile geckos, and breeding females.

If your gecko is tolerant of handling to some degree then of course handling the animal is an option. Things to bare in mind with this species is they are quite flighty, and will jump readily, even if there is no clear target for them to reach. You should also be aware that Crested geckos are capable of dropping their tails if they feel stressed on scared. Rough handling around the tail area is most likely to cause this. Whilst the tail will not grow back, in general it will not cause the animal too many problems, and should not require a vets visit.

Breeding Crested Geckos

Crested geckos will reach sexual maturity at different ages, generally depending on sex. Males will typically be able to mate at around 9 months (however size issues may make this a risky proposal if the femal they attempt to mate with is much larger than they are). Females on the other hand become sexually mature at around 1 year. However age is not the principle concern when considering if your female is at an appropriate age to breed. While we are not, in general, great believers in the concept of 'minimum breeding weight', in Crested geckos females should be at least 35g before you consider breeding them. They are very prone to weight loss during the breeding season, and nutritional imbalance is also an issue. It is for this reason that we suggest that you should weight till the female has reached this weight and is at least 18 months old before introducing her to a male.