Caring for Varanus acanthurus, the Ackies Monitor – June 2013

By Max Weissman

Varanus acanthurus is a species of monitor lizard found widely throughout most of Australia. Commonly referred to as Ackie Monitors or Spiny Tailed Monitors, they are found in arid regions or scrubland environments throughout Western Australia, Northern Territory, and parts of Queensland. They live near rocky outcroppings, and when frightened they retreat into small crevices of the rock. They will fill their bodies with air to wedge into the rocks and fold their hard, spiny tails in front of the rock face to discourage predators from trying to pull them out. They live in humid burrows that they dig deep into the ground to escape the midday heat and also to control their hydration and temperature levels. Ackie Monitors are a popular pet monitor species to own because they are inquisitive, active, and have great colors and patterns, and relatively small adult size.

Ackie Monitors grow to reach an average length of 24 – 28 inches, with males usually having a thicker, heavier set head and neck than the females.  Ackie Monitors, like most monitors, can live a long time with an average life span of 15 to 20 years if properly housed and maintained.

When housing any Ackie Monitor keep in mind they actively hunt, explore, bask, and burrow. With this in mind I would recommend a 48” x 24” x 24” or larger glass terrarium from Creative Habitat, which we sell online and in our stores, or you can make a custom enclosure. It is best to give them a tall cage to give them a deep substrate to burrow into. Remember, if you ever question the size of your cage, bigger is always better with monitor species. Also, with cages that have screen lids you can add a cover made of acrylic, foil or a towel to help maintain humidity levels in the cage. However,  if you keep at least 10 to 12 inches of moist substrate in the cage, and an appropriate size water bowl, humidity levels on the top level can dip very low as Ackie Monitors will retreat into their burrows to control hydration and shedding.

Happily peeking out of a burrow! 

Since Ackie Monitors come from Australia, they should be provided with a basking zone surface temperature (which is best measured with a temp gun) of around 130 degrees Fahrenheit or hotter, while the air temperature measured by a probe thermometer is around 90 degrees Fahrenheit. You must maintain the cooler side’s air temperature at no lower than 70 degrees Fahrenheit and no warmer than 80 degrees Fahrenheit for your ackies to have optimal temperatures for thermoregulation.

This is critical since all reptiles are ectothermic and need to regulate their body temperatures by the temperatures of their environment. The best way to do this is by giving them as many areas of different temperatures as possible. Also, while some breeders have successfully kept and breed Ackie Monitors without UVB lighting, I highly recommend you use UVB lighting with your own monitors, since Ackie Monitors are basking lizards and in the wild they are exposed to UVB. Using a Mercury Vapor Bulb provides the animal with both UVB and heat all in one bulb. Deep Dome light fixtures are the best way to house your bulbs because they do not protrude out of the bottom of your fixture. Do not leave any visible light on at night as this can stress your animal; I recommend that you keep them on a 12-hour cycle (12 hours of light and 12 hours of darkness). This can be accomplished simply by turning the light on in the morning and turning it of at night, or by a use of a timer. With this being said, if you are an experienced monitor owner or feel comfortable in doing such you can try a more natural approach with cycling the lights. This means going down to as little as 8 hours a day through the winter months, as long as you maintain the proper temperatures, and as much as 14 hours a day in the summer months, again making sure you are constantly reading and maintaining the temperatures within an acceptable range. If the daylight heat bulb you are using does not reaching the optimal temperatures you can add ceramic heat emitters. The ceramic heat emitters do not produce any light but put off a good deal of heat. Lamp stands can also be a good way to help keep temperatures at a constant by keeping the light at just the right height.

Ackie Monitors love to burrow and need a substrate to hold humidity and the shape of the burrows.  Compressed coconut substrate, when lightly packed in the cage, holds its shape and humidity nicely. And, if mixed with clay based substrates such as Zoo Med’s Excavator substrate makes a great combo at a ratio of 1 part excavator to 3 parts coconut substrate. Most coconut, cypress, and sterile plantation soils are all highly recommended.  They make a great mix when added in with vermiculite and play sand in a ratio of 1 part vermiculite : 1 part play sand : 3 parts soil. Making the substrate layer thick and moist will aid in keeping your monitor hydrated and shedding properly. There are a variety of ways to provide hiding spots, which include cork bark stacks, half logsflat pieces of wood, thick layers of bedding and moss,caves, and lots of cover in the form of fake plants. A monitor’s need to hide and stay warm can be duly accomplished in the form of providing a stack of cork bark or wood underneath the basking light, with the highest level being a few inches away and forming the hottest spot in the cage, with the lower levels being significantly cooler. This will allow your Ackie Monitor to thermoregulate its temperature and still feel secure. The key to success in a monitor’s cage is to offer the lizard as many choices as possible. The more options the monitor has to utilize for thermoregulating, the better it will do.

One of the author’s ackies enjoying some natural sunlight! 

An effective way to keep an Ackie Monitor hydrated is to keep a water bowl large enough for the monitor to soak in within the cage, so that if it wants to climb in, it can. They tend to like the surface and air to be dry and their burrows to be moist. A good way to keep burrows moist is to add water into them when the animal is out and about and not in the burrow. Also misting the cage once or twice a day will help keep the humidity levels up and aid in proper shedding and hydration.

Ackie Monitors in captivity have been known to take a wide range of prey items, including but not limited to: micecrickets, hissing cockroaches, dubia roaches,mealworms, Zoo Med’s canned food diets, snails, eggs (chicken and quail), and shrimp. It should be noted that just because a monitor can eat something, that does not mean that it is a suitable food. While a wide variety of food will be accepted, some foods are more readily eaten than others and some are far more appropriate as food items than others. While these monitors will eat dog and cat food, I do not recommend it as a part of the diet. Ideally, a diet consisting almost entirely of whole prey items with a small portion consisting of the raw turkey and egg diet, which was pioneered by the San Diego Zoo, is best.

Suitable whole prey items include hissing cockroaches, dubia roaches, lobster roaches; mice (avoid unweaned rodents as they are high in fat and low in calcium and other nutrients). All food items, with the exception of rodents, should be dusted with a high quality calcium and/or vitamin powder, such as Sticky Tongue Farms MinerAll Indoor Formula or Repashy’s Calcium Plus.Young monitors can be kept mainly on crickets, mealworms, and small roaches, while adult monitors can be fed the entire range of possible food items. Rodents should be fed in moderation, leaning on the side of fewer rodents than insects. Captive monitors rarely, if ever, get the same kind of exercise wild monitors do, and care should be taken to ensure that an adult monitor does not become obese.

Some of the author’s baby Ackies basking

In addition to being fascinating and hardy captives, Ackie Monitors are relatively easy to handle. With calm, confident handling on a regular (but not necessarily frequent) basis, these monitors can learn to tolerate and even enjoy human interaction. Care must be given to allow the monitor plenty of time to acclimate before any attempts at developing an owner-monitor bond are made. Once the monitor shows a healthy appetite and eats readily, and does so regularly, start handling it for just a few minutes at a time daily. If the monitor continues to eat and does not spend the time immediately after handling buried beneath the substrate, avoiding you at all costs, increase the handling time slowly but surely, until the monitor does not mind being out for extended periods of time. Always be sure to read your monitor’s behavior: If it hides and does not move for days on end after being handled, decrease handling time and frequency. With patience, eventually these monitors can and will become tame.

Captive Husbandry of the Fire Skink – January 2013

By Jennifer Greene

Fire skinks, or Riopa fernandi, are arguably some of the cutest lizards out there.  With big, doe-like eyes set on a cute little face, bright colors and little legs on a long body, they are capable of making even non-reptile lovers squeal about how cute they are.  Their common name arises from the vivid red coloration on their sides, which connects to red strips down the side of their neck and up into bright red cheeks.  They typically have a black base color with a white checkered chin, and their backs are often a golden tan, with some individuals having a redder color instead.  They are on the smaller end in size, with mature adults reaching between 14 and 20” depending on tail length.   Their relatively small adult size compared to other pet lizards, in combination with their adorable faces and ease of care, make them quite delightful pets to keep.  Captive bred skinks can be downright outgoing, often coming out to see their owners and check for more food.  As rewarding as these little skinks can be, they are not often kept, or not kept for extended periods of time.  They are seen as either too difficult for the beginner (not the case!) or too basic for the more experienced keeper.  My hope is to help the beginner embrace these adorable creatures, and to highlight the rewards of keeping them to encourage more herpers to give them a shot.

Fire skinks can regrow their tail, much like this captive bred baby is doing!

Most fire skinks available to reptile keepers today are wild caught in origin, with most originating from a handful of countries in West Africa, often the same countries that baby ball pythons come from.  A small number of keepers have successfully bred their fire skinks (myself included), so captive bred babies can be available on occasion – it just takes patience sometimes to find them.  Wild caught skinks are not usually difficult to get acclimated to captivity, especially when set up properly and given time to settle in.  Captive bred babies do tend to be more outgoing than their wild caught cousins, but regardless of your skink’s origins, their care is the same.

I prefer to keep them in a relatively large cage, as they can be extremely active and will utilize all the space.  You can maintain one or two in a cage as small as a 20 long, but I highly recommend a cage at least 36” x 16” x 16”.  I keep my adult pair in an ExoTerra terrarium that measures 36” long by 24” tall by 18” deep, and I routinely see them using the entire cage.  In a cage like the ExoTerra one that I use, you can offer them a nice thick layer of substrate to burrow into, which they will love.  I use a combination of cypress mulch, Eco Earth, and orchid bark to achieve a nice, natural looking appearance that maintains humidity well and does not require frequent changing of the substrate.  I check the cage daily for feces, and once a week stir up the bedding and add fresh water to keep it moist.

I rarely actually see my skinks in their water bowl, but I do find fresh feces in the bowl about every other day.  Because they are prone to pooping in their water dish, I prefer to offer them a bowl big enough for them to climb into, and for mine I use a ZooMed Large Corner Dish.  I furnish their cage with a variety of items for them to climb on and around, and they really seem to love clambering up inside of cork tubes to bask under the lights.  I have a large tube on each side of the cage, and a few large and medium pieces of cork flats piled throughout their cage.  In addition, I added some fake vines to provide some foliage in the cage and visual barriers for them.  Using fake or live foliage helps make the cage look a little nicer, and provides cover for your skinks to hide behind and feel safe within their cage.  You may even see them peeking out at you from under the leaves!

One of the most important things about skink housing is something that doesn’t even get placed directly in the cage, but instead over the top: lighting!  As terrestrial skinks, these little critters don’t require exceptionally intense heat or light, but they do need heat and UVB provided during the day.  In the large cage that I use, a 100 watt powersun bulb provides all the basking light and UVB, and to illuminate the rest of the cage I use the new ExoTerra Ion bulbs.  I really like using the Powersun bulb on larger cages to provide heat and UVB, as the skinks really seem to thrive with the ability to get close to the light as needed.  The new ExoTerra Ion bulbs are nice, extremely bright bulbs that do not put out measurable amounts of UVB, making them ideal for illuminating reptile cages that already have a source of UVB.  Putting too many UVB lights on one cage has the potential to irritate the eyes of yourreptiles, and does not give them the option to escape UVB exposure if they feel the need to.  The Ion bulbs are super bright, and that in combination with their low cost makes them ideal for illuminating just about any cage you have.

 

My favorite bulb for most diurnal reptiles – the fantastic Powersun!

Basking temperatures can reach up to 95 degrees Fahrenheit as long as the cool side remains below 80 degrees.  How you achieve these temperatures is up to you; I use only the Powersun bulb in my cage during the day, and at night my skinks have a 75 watt infrared bulb to keep cage temperatures from dropping too low.  Exactly what wattages you use for your own cage at home is something you may need to tinker with to get it just right.  A warmer home (75 to 80 degrees) will not require as hot of a basking light, nor would it need a night time heat source.  A cooler home (65 to 70 degrees) would probably require higher wattage bulbs.  Using a thermostat or rheostat to help monitor temperatures within the range you prefer can make your life much simpler, rather than switching out multiple wattages depending on the time of year.  I also use a Zilla Power Center Digital Timer, which makes my life immensely easier because it switches all my lights on and off on its own.  All the lights are automated, which just leaves the daily maintenance to cleaning out the water and feeding my skinks!

Feeding your skinks can be one of the most enjoyable aspects of their care – they are often very enthusiastic feeders, and readily consume most live feeder insects.  The staple of the diet can consist of primarily crickets and mealworms, with full grown adult skinks easily consuming 1” crickets, giant mealworms, or superworms.  In addition, I highly recommend including roaches in your skink’s diet.  Mine happily eat dubia and hissing cockroaches, and I do not doubt that they will consume just about any species you can order online or find at your nearest reptile expo. Waxworms, reptiworms, silkworms, and hornworms all can and should be added to your skink’s diet whenever possible, as the variety in their diet will help your skinks grow and thrive their best.  On top of all that, they will often also eat canned insects, such as canned caterpillars, grasshoppers, and even snails, so there is no excuse for not providing a varied diet for your lizards!

Adult Skinks can easily eat superworms

Waxworms are good treats to feed occasionally too

Illustrating the size difference between regular mealworms and giants – both are acceptable food items!

Whenever offering live insects, it is also important to dust them with a high quality reptile calcium and/or multivitamin.  I use and highly recommend either the ZooMed Reptivite (with D3 for lizards kept indoors), or the Repashy Calcium Plus, as both have a great balance of calcium, multivitamins and vitamin D3.  While you may be making quite the effort to provide your skinks with as varied a diet as possible, it does not come close to approaching the dozens or hundreds of different insects and small animals they would consume in the wild.  For this reason, it is important to dust your skinks’ food at least every other feeding, or as per the instructions on your calcium or multivitamin supplement.

When it comes to handling your skinks, it really depends on your skink and how well it reacts to your presence.  This is where it can pay off to pick up a captive bred baby, as they are often already well-accustomed to human interaction and handling.  Certain long term captive skinks mind it less than others as well, and even originally skittish skinks can become habituated to their owners with time.  The key is patience and time: feeding your skinks well and letting them get used to you for several weeks or months will give them time to settle in and learn that you are not going to harm them.  Once they are well established and feeding well for you, you can attempt to coax them out or handle them for short periods of time.  Not all skinks enjoy handling, especially at first, and they can be extremely squirmy and fast, so you may want a spotter around for the first few handling sessions in case your skink escapes!  Most skinks are perfectly happy if they are rarely, if ever, handled, so do not feel as though you need to handle your skinks for them to do well.  If anything, they would probably love to be left alone entirely, and instead will come out to check out their surroundings and watch what is happening outside their cage.

Any of these supplements are suitable for your skinks!

Calm, confident handling is key to teaching your skink to accepting human interaction!

Fire Skinks are cute, brilliantly colored little lizards that can be incredible pets for the keeper looking for a smaller species of lizard to display in their home.  Their sturdiness and ease of care coupled with how frankly adorable they are makes it hard not to love them as a fantastic beginner lizard or fun side project for the experienced keeper.  Breeding them is also fairly easy and straightforward, and once established they can be extremely prolific.  Check back with us next month to see a Breeding Spotlight take you through step by step on how to condition, breed, incubate, and raise Fire Skinks of your own!