Ackie monitors (Varanus acanthurus) are 24” long, diurnal, terrestrial lizards native to northwest Australia. They prefer arid habitats with plenty of rocks and spinifex grass for cover, as they spend most of their time in burrows and crevices.
Ackie monitors have long, slender bodies with a sharply taped head, long pink tongue, long neck, rounded belly, sharp claws, and a mildly spiked tail. They are typically yellow- to reddish-brown in color, with a pattern of pale rings on their back and a ringed tail. The scales on most of the body are smooth, with the tail being an exception.
Ackie monitors are among the most popular pet monitors due to their manageable size and bold, intelligent dispositions. However, due to their husbandry requirements, they are still an intermediate-level reptile. With good care, they can live up to 15+ years.
Minimum terrarium size for ackie monitors
The absolute minimum enclosure size for a single ackie is 5’L x 2.5’W x 4’H. This may seem huge, but keep in mind that monitor lizards are particularly active, and you need plenty of room to accommodate a generous substrate layer. Of course, if you can manage it, larger is always better!
Housing multiple ackie monitors in the same enclosure is generally not advised.
Do ackie monitors need UVB?
Yes! Although they have been proven to survive and breed without access to UVB, using UVB light in captivity is still best practice. UVB lighting helps provide a clear day/night cycle, supplies all of the vitamin D that your pet needs, strengthens the immune system, facilitates better digestion, and provides other benefits.
Here are the best UVB bulbs for ackies housed in a 5’x2.5’x4’ enclosure:
- Zoo Med Reptisun T5 HO 10.0, 34”
- Arcadia Desert 12%, 34”
For best results, house the UVB bulbs in a reflective fixture like the Arcadia ProT5. Position the lamp on the same side of the terrarium as the heat lamp. The UVB lamp should be mounted inside the enclosure, with the basking platform placed so the lizard’s back will be 12-15” below the lamp.
Ackies are also likely to benefit from plant grow lights as part of their environment as well. Add a ~6500K LED or T5 HO fluorescent grow lamp to provide extra illumination, as well as help any live plants in the enclosure to thrive.
Lights should be on for 11 hours/day during winter and 13 hours/day during summer to simulate seasonal changes in day length. All lamps should be turned off at night.
Best temperature for ackie monitors
Ackie monitors should have a basking surface temperature of 158-172°F, as measured by an infrared thermometer. Juvenile monitors may prefer cooler basking temperatures. To provide an optimal selection of temperatures for the lizard to choose from, use a Retes Stack for the basking surface.
The cool side should be between 75-82°F. Providing an escape from the heat is essential for healthy thermoregulation.
Provide heat for your ackie with a cluster of at least two halogen heat bulbs placed above the basking platform. Halogen bulbs are the best way to imitate the warmth of sunlight indoors, and considered to be a superior form of reptile heating by experts. Do not use ceramic heat emitters (CHEs), red bulbs, or blue bulbs, as these are not as effective.
Heating should be turned off at night.
Best humidity levels for ackie monitors
Ackies prefer a dry to moderate-humidity environment with free access to a humid burrow. Air humidity should be between 20-50%, and measured by a digital hygrometer on the wall of the enclosure. Humidity in the burrow should be much higher (80%+), and measured via digital probe hygrometer, with the probe placed inside the burrow.
Pouring water directly into the substrate can be very helpful for maintaining both aspects of humidity.
Best substrate for ackie monitors
Providing a layer of naturalistic substrate (“bedding”) in the enclosure will help maintain correct humidity, cushion the lizard’s body, provide a digging medium, and also help make your enclosure more attractive!
We recommend the following substrates for ackies:
- Zoo Med ReptiSand
- Exo Terra Desert Sand
- Play sand
Substrate should be at least 12” deep (absolute minimum) and completely replaced every 3-4 months. Remove poop and urates daily, along with any contaminated substrate.
How to decorate an ackie monitor terrarium
An empty enclosure makes for a bored lizard, reducing its quality of life. Keep your pet entertained and engaged with its environment with the strategic use of décor items that encourage it to exercise natural behaviors!
Here are some ideas to get your started:
- sturdy branches
- large hollow logs
- live or artificial foliage (ex: grasses)
Training and designing enrichment activities are also good ways to help keep your monitor engaged, as well as provide a nice opportunity for bonding!
What to feed to an ackie monitor
Ackies are insectivores, which means that they need to eat a diet of mostly insects in order to get the nutrition that their bodies need. Offer food every morning. Juveniles should get as much as they can eat in one day, but subadults and adults should only be allowed as much as they can eat in a 5-10 minute period.
Feeder insects for ackie monitors: crickets, dubia roaches, red runner roaches, black soldier fly larvae, mealworms, superworms, darkling beetles, hornworms, silkworms, snails, grasshoppers, scorpions, centipedes
You will also need calcium and vitamin supplements to prevent your lizard from developing a deficiency. Repashy Calcium Plus LoD, lightly dusted on all insects. It’s okay to occasionally skip a dusting.
You will also need a water bowl to help keep your ackie hydrated. Change the water at least twice a week and scrub the bowl with a reptile-safe disinfectant weekly, or whenever it becomes soiled.
How to handle your ackie monitor
Reptiles generally don’t appreciate petting and handling in the same way that dogs and cats do. Ackies are capable of becoming quite tame, but they still require plenty of patience and work.
If you want to build a trusting relationship with your pet ackie, you will need to develop a firm foundation of positive interactions. Offering food from feeding tweezers works well as an initial bribe, and it’s best to get the lizard to come to you rather than simply grabbing it.
Here are some more tips for success:
- Don’t grab the lizard from above. Instead, scoop from below.
- Support as much of its body as possible.
- Let it climb onto your hand/arm rather than picking it up whenever possible.
- Start with short handling sessions at first, then gradually make them longer.
- Put the lizard back in its enclosure only when it’s calm.
*This care sheet contains only very basic information. Although it’s a good introduction, please further your research with high-quality sources. The more you know, the better you will be able to care for your pet! We recommend the following sources:
- The ReptiFiles Ackie Monitor Care Guide
- Ackie Monitor Keepers
- “A Guide to Australian Monitors in Captivity” by Danny Brown
"varanus acanthurus" by Joachim S. Müller is licensed under CC BY-NC-SA 2.0