Underwoodisaurus milli – Thick-tailed Gecko
Nephrurus levis – Smooth Knob-tailed Gecko
Adult Size: 10-15cm
Housing: Single, Pair or Trio 60x30cm or larger
Lifespan: 7-10 years
Lighting: LED Optional, low wattage Heat, Low Output Uvb Optional
Temperatures: Hot Spot 26-28C Cool Side 20C
Diet: Variety of insect.
Ease of Care: Easy
The Smooth Knob-tail Gecko and the Thick Tailed Gecko are the two most common terrestrial Geckos kept in captivity in Australian Collections. Their popularity is mostly due to their vast distribution across Southern (levis) and Eastern Australia (milli), their naturally docile temperament, as well as their ease of care and willingness to breed. These Geckos are mainly active at night (nocturnal) and have a very social nature. In the wild it is common to find large groups of U. milli (majority being female) living together in burrows and dens to conserve heat, some even having communal laying sites. Adults can grow up to 10-15cm with Females being larger. While these Geckos are not a pet that requires or desires a lot of handling, they make excellent display animals exhibiting unusual behaviours at dusk, like wiggling their tails in excitement in the hunt for food, and excavating everything in the attempt to make a new burrow.
Their under body is generally a translucent white and their dorsal surface can range from dark purplish-blacks to reddish-brown tones to pale yellow. Generally their patterning consists of white raised cone shaped tubercles, which aid in camouflage. A Thick tail is generally a sign of good health, although young individuals and females who have recently laid eggs can have a more slender appearance. These Geckos have the ability to drop their tails when stressed as a defence mechanism, they can regenerate their tails, although they will often look dull in comparison.
Knob-tailed Geckos thrive in social groups consisting of a single male and multiple females. A pair or trio can be adequately housed in a glass mesh top vivarium measuring 60x30cm or larger (the bigger the better). ExoTerra and ReptileOne terrariums are all ideal as they are spacious, secure and well ventilated. While they may not be excellent escape artists, security is important when protecting your geckos from other pests and pets. It is a good idea to only keep similarly sized Geckos together, as bite sized Geckos look incredibly tasty to other Geckos and smaller individuals may be harassed. Ensure your enclosure is placed in a room that is well lit, away from direct sunlight, quiet and away from frequent activity, ideally with a stable temperature no higher than 20-25C. These Gecko’s do not tolerate temperatures above 30C for extended periods of time, they are however very cold weather resistant.
We recommend Washed Terrarium Sand, Riverbed Sand, Red Desert Sand or Zoo-Med Excavator. These Geckos are known to stress when housed on artificial and unnatural substrates like paper towel. Sand allows for natural behaviours like digging burrows which seem essential to their behavioural needs.
In the wild, the sun provides the Gecko with heat, light and UV radiation. These animals are naturally Nocturnal, but this does not mean that they are only active by night. Both species have been observed in the wild, and in captive studies, basking in full and shaded sunlight particularly in late afternoon. In captivity it is vital that we replicate this to the best of our ability for the health of the animal. The spectrums of Light are easier to understand if we part them into four sections.
– ‘visual light spectrums’ also plays an important role. This can often be provided with ‘broad spectrum’ basking lights, plant growth LED’s or ‘bright white’ fluorescent lighting. In the case of Gecko’s, we prefer using an ExoTerra Visual Light© as they are Bright in Visual Spectrums without being a harsh white.
-UVA- long wave ultraviolet, ranges from 320-400nm and is essential for reptile vision, wellbeing and pupil retraction, present in ExoTerra Visual Light© Globes.
-UVB Medium wave ultraviolet B, ranges from 290-32 nm and it essential for synthesis of vitamin D3 metabolically. Although not ‘essential’ Geckos have been observed basking in refracted Uvb wavelengths in the wild and captivity and seem to respond well. We suggest a 2.0 Compact.
-UVC- Short wave ultraviolet C (the bad guy) ranges from 180-290 nm and is dangerous and a health hazard. Some globes can emit these particular wavelengths and for this reason we suggest using a visual light lamp in conjunction with a low watt Uvb Globe.
It is important to replace visual light globes every 12 months and Uvb globes every 6 months. The wavelengths emitted decrease and fade over time, although visually the globe looks well lit, the globe is of little benefit after these time frames.
Because Geckos require very little heating, we suggest using a 5w-7w heat mat down one end of the Terrarium, depending on the size of the enclosure. You are aiming for 28C with a temperature gradient down to 20C. If the Terrarium is large enough, a very small wattage globe (15w or equivalent) may be used to create a small temperature rise for a basking site, although in most cases unnecessary. It is important to remember to position your terrarium in a cool room away from windows or direct sunlight. These Geckos do not tolerate excessively high temperatures for extended periods of time.
Hiding places are essential for your naturally shy (and nocturnal) Gecko. More is better. Place one hide over the heat source, and one on the cool side, provide another that has a moist peat moss inside as a place for your gecko to retreat that holds humidity to aid in shedding. We recommend ExoTerra Reptile Den (image to the left and below) as it allows your gecko’s to be visible for viewing without completely disturbing them. We also recommend ExoTerra Reptile Cave’s as they are light and spacious and allow an almost completely enclosed hide, which will make your Gecko’s feel secure. Half log ornaments and up-turned terracotta pots are also ideal.
Geckos are insectivorous, meaning their diet consists completely of insects. Crickets, wood-roaches, silkworms, fly larvae, and mini-mealworms are all appropriate food items. Variety should be given as not one single food item provides complete nutrition. Food items should never be larger than the space between their eyes as choking is a hazard and pressure on the spine while swallowing.
Feeding should occur when you get home from work, or after you’ve had dinner yourself, as this is when your Geckos begin to venture out from their burrows to hunt. It’s hard to imagine, but Thick-tailed Geckos are avid hunters and get incredibly mobile in the hunt for prey. At times they can run and pounce and even wave their tails in anticipation. Uneaten prey should be removed from the enclosure after feeding or the following morning, as the can be a hazard by nibbling on your Geckos as they sleep the following day.
Your feeder insects should always be fed well for at least two hours before being fed to your Geckos. You are what you eat, and so is their food. If you are able to feed your insects a diet that is high in vitamins and minerals, the benefit will pass on to your Dragon. Offer a specialised ‘Gut load’ or make your own with Reptile pellet feed, always offer your live feed fresh carrot. Insects should be dusted before feeding, every second feed with calcium with D3 and Multivitamin. We use, trust and recommend Rep-Cal supplements as a premium and safer alternative.
Provide your Gecko’s with a shallow sturdy water dish. Provide clean water regularly and remember to rinse and scrub the dish at least once a week to prevent bacterial growth. Geckos may wade in the water, but they will tend not to drink from it. Geckos are accustomed to licking water droplets from their faces (with their long tongue) or from plants and rocks in the wild. In captivity they will likely lick droplets from the glass walls on the enclosure. Mist with room temperature water 3 times a week. Don’t be shy on gently spraying your gecko down, as the moisture will also aid in shedding, and really, who doesn’t want to see your Gecko lick their own eye balls.
Handling should be kept to a minimum with gravid (pregnant) females and very young individuals. Gecko’s stress very easily, although handling is possible it should be kept to a minimum. Gecko’s do have a defence mechanism to drop their tails when they feel threatened (usually a warning bark will sound before this happens) it’s a loss of valuable fat store and stressful for the animal. The tail will grow back, although it will never look the same.
Thick-Tailed Gecko’s can attain breeding age within 12 months (although more commonly at 18months to 2 years of age.) Size and sexual maturity are reached at variable times as growth is determined by health and diet. Sexing mature specimens is simple; males have hemipenal bulges and spurs (two bulges on the underside below the vent, and spurs on the outer sides at the base of his tail.)
It is incredibly important that you feed your females regularly and abundantly, the production of eggs can take a lot of nutrient from her body, and it is important that you replace these nutrients, vitamins and minerals to keep her (and her young) in good health.
Your Geckos will naturally feel the slight temperature changed between summer and winter, it’s almost impossible to fool reptiles from the natural seasons beyond the walls of their enclosure. Spring will be the time that your males will begin to court your females, they will follow and bark and seem to dance around your females. Until she is ready she will likely ignore and wriggle away from him. When the pair are ready, the male will bite the nape of the female’s neck and manoeuvre his tail below hers.
The female is capable of holding semen to produce anywhere between 4 and 9 clutches each generally consisting of 2 eggs, although it is likely your male will try the move a few times during the coming months between clutches. Unless an abnormal amount of aggression is being shown, try not to separate individuals, as they tend to experience depression when kept alone. You will notice the female will begin to swell in size and you may even see the bulges of the eggs within her abdomen. It is vitally important that you provide a comfortable place for your female to deposit her eggs. If she is not presented with an appropriate place she will hold them and lay them in an inappropriate area (which is stressful and will be detrimental to the health of her young) or she will choose not to lay and become egg bound (which can lead to death.) Provide a deep digging box up to 20cm deep of moist sand; I tend to use a dark Tupperware container with a hole cut in the lid. The darkness provides security, although she will likely dig to the very bottom to deposit her eggs. If you choose to incubate the eggs use a mix of coarse vermiculite (one part water to one part vermiculite by weight) generally the first clutch is infertile, so don’t feel too disappointed! Fertile eggs will generally hatch within 45-70 days at 29C.
Feel free to talk to us about setting up an incubator, we’re more than happy to help you through the process!
Common health issues
Intestinal Parasites; while most reptiles have a normal level of intestinal parasites or worms (commonly coccidia) captive environmental stresses can lead these levels to sky rocket and effect the health of your Reptile. It is a good idea to take a fresh faecal sample to your Reptile specialist veterinarian for a test at the first sign of illness, and a treatment can be prescribed. Weight loss, sunken in eyes, stunted growth, lethargy, and diarrhoea are all common signs.
Metabolic Bone Disease (MBD); Calcium and D3 Deficiency, caused by a lack of adequate ultraviolet radiation, dietary imbalance or lack of supplementation. Signs include lethargy, muscle twitches and spasms, broken or soft bones, tail deformations and splayed hips, under bite. Treatment for these issues will need a consultation with your vet.
Dysecdysis; Abnormal or incomplete shedding. While a Gecko’s shed may come off in patches, low humidity or infrequent bathing can result in retained shed. Retained shed may pinch tails and toes and result in docking. In extreme cases, patchy and inconsistent shedding may be a sign of external parasites. Bathing and misting will often assist difficult sheds.
Dehydration; Young Gecko’s in particular can dehydrate in the summer heat, regular misting is required. A water bowl should always be provided and regular bathing is often helpful.
Mites; Gecko’s may seem irritable and scratch frequently, sometimes sitting almost full submerged in the water dish. Small mites are often visible around the eyes. Mite sprays are available, a full clean out of vivarium, equipment, ornaments and surrounds will be required to rid the environment.
Respiratory Infections; Often caused by stress, low temperatures and high humidity, or dust from calcium sands, respiratory infections give symptoms similar to the flu. Symptoms include Coughing, wheezing, mucus from mouth or nostrils, continual gaping, heavy breathing and lethargy. A vet visit is required for prescription medication to cure a respiratory infection.
Eye infections; closed, irritated, swollen, or mucus covered eyes, often caused by scratches, or dust. Eye infections can turn sour quickly without treatment from a vet.
Impaction; when a food item, solid or substrate has become lodged in the gut lining preventing defecation and putting pressure on the spine. Commonly seen in juveniles who are fed Mealworms, or have ingested coco-fibre, bark, or calcium sands. These experiences are made worse when the animal is dehydrated, or kept in an improper temperature gradient, or fed too early or too late in the day. Often the animal will attempt to regurgitate (semi digested mealworms), or will be seen gagging or wriggling. In extreme cases the animal will experience lethargy, have a slumped posture, and refuse to move. A luke-warm bath and gentle massaging of the underside may help the blockage pass. Failure to pass, a vet visit will be required to assess the situation and an enema or surgery may be required.
Hypervitaminosis: Commonly an over supplementation of Vitamin A. In most cases this is only possible when using vitamin supplements containing Vit A (Herptivite multivitamin does not contain Vitamin A, rather the building blocks for the animal to create it as required). Signs will be swelling around the eyes, limbs, throat and body. Contact your local exotics veterinarian for an appointment.
A correct setup, temperature gradient, lighting and diet is the best prevention for most common issues. Abnormal behaviours should be looked over by a Reptile Veterinarian. These behaviours may include star gazing, disorientation, head spins, rolling, twitching, tremors, lethargy, loss of appetite, hunched over stature and diarrhoea.
Feeding: Gecko’s should be fed nightly.
Cleaning: Daily spot cleaning should be performed with a Sand Sieve, and the substrate should be fully removed at least every 2-3 months depending on spoilage. At this point, a good quality and safe enclosure cleaner can be used to sanitize the environment.
Health & Hygiene
Reptiles do carry salmonella, it is always a good idea to wash your hands before and after handling. Particularly with young children.
The heat and lighting involved in a bearded dragon’s setup do get quite hot, be sure to turn all lamps off and let cool before handling fittings or bulbs. For the safety and longevity of your lighting and heating equipment, always run heating and lighting through a surge protected power board
Gecko’s, like all reptiles and amphibians in NSW are protected species, by law a Permit is required to keep one. A Companion animal will allow you to keep just one Reptile, where as a Basic Class One Licence will allow you to keep multiples, and different species. Applying for your permit is easy and can be done in store within about 10-15 minutes or online at http://www.environment.nsw.gov.au applicants must be over the age of 16. A valid, in date Reptile keepers licence must be visually cited in store to purchase an animal, accompanied by the licence holder.
Best of luck!
If you have any further queries or questions, please don’t be afraid to ask one of our helpful staff members in store, on the phone or by email.
- Terrarium Enclosure 60x45cm is ideal
- Heat Mat; Aim for low wattage, but enough to heat to get one area to 28C.
- Uvb Light; Low Output; Optional.
- Visual Light; Visual Light© or Natural Light© Recommended.
- Thermometer; A good Dual Zone Thermometer with Probe is ideal.
- Thermostat; highly recommended for those hot summer days to prevent overheating.
- Timer; A good thermostat will generally do this for you, but a timer makes life easier.
- Substrate; we recommend the Sands and Excavator Clay
- Hides; we recommend half logs and hide ornaments.
- Background; Easy to install, natural looking, and climbable.
- Artificial Plants; These enable young Geckos to hide and feel secure.
- Water Bowl
- Food Dish
- Live food; Crickets, Roaches, Black Soldier Fly Pupae are great starters.
- Supplements; Essential! A good quality Calcium with D3 and Multivitamin.
- Cricket Keeper; helpful in deterring escapes and making cricket keeping easy.
- Sand Sieve
- Feeding Tweezers
- Enclosure Cleaning Sanitizer
- Shed-Aid Spray: Highly recommended.