The Ackie Monitor (Varanus acanthurus), also known as the Spiny-tailed Monitor or Ridge-tailed Monitor, is widely considered the ideal entry point into monitor keeping. It is alert, active and genuinely interactive, forming associations with its keeper over time in a way few reptiles do. Adults reach 55 to 70 cm and come from the rocky, arid landscapes of northern and central Australia. Despite their smaller size, Ackies have all the demanding husbandry requirements of a large monitor: they must be respected as the intelligent, heat-seeking animals they are.
A wildlife keeper's licence is required in Queensland. See our Queensland Reptile Licence Guide before purchasing.
Enclosure
Ackies are active foragers and diggers that need substantial floor space and deep substrate. A single adult requires a minimum enclosure of around 150 x 60 x 75 cm (roughly 5 x 2 x 2.5 ft), and larger is always better. Floor space is the priority over height for this ground-dwelling species, though they will make use of a low rock or branch for basking.
Provide a deep substrate of a sand and soil mix, at least 15 to 20 cm deep, that holds a burrow. This serves both as a thermoregulatory resource and as enrichment. Include several rock stacks or cork hides that create crevices the monitor can retreat into, a sturdy water bowl, and a secure escape-proof lid.
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Heating
Heat is the single most important aspect of Ackie Monitor husbandry, and the most commonly underestimated. These animals come from environments where the rock surface temperature in the sun can exceed 60°C, and they depend on accessing that heat to properly digest food and drive their metabolism.
- Basking surface temperature: 50 to 60°C at the hottest point directly under the lamp cluster
- Warm ambient (mid-enclosure): 28 to 32°C
- Cool end: 25 to 28°C
- Night: allow to drop to around 20 to 22°C
Create the basking zone with a cluster of two or three basking lamps (not a single lamp) directed at a flat rock or tile. This creates a broad, natural surface hot zone. Measure the surface temperature with an infrared temperature gun, not a standard thermometer: the surface temp is what matters, not the air temp above it. Connect all heat sources to a thermostat. Browse our heating and thermostat range.
UVB Lighting
Ackie Monitors are diurnal and require strong, high-quality UVB. Use a T5 high-output UVB tube covering most of the enclosure and positioned to allow the animal to bask within effective UV range. Run lighting for 10 to 12 hours per day and replace the tube every 6 to 12 months. UVB output declines long before the lamp stops producing visible light. Browse our UVB lighting range.
Feeding
Primarily insectivorous with some vertebrate prey for adults. Monitors have fast metabolisms and need regular, varied feeding.
- Juveniles: feed daily, offering a variety of live insects such as crickets, woodies, roaches, and the occasional small waxworm. Juveniles grow rapidly and need consistent protein.
- Adults: feed every 2 to 3 days. Offer a varied diet of live insects, plus the occasional small pinkie mouse or lean meat strip for adults. Whole prey is preferable to meat alone.
Gut-load feeder insects for 24 to 48 hours before offering and dust with calcium at every feeding. Use a reptile multivitamin periodically. Obesity is a real risk in captive monitors: a healthy Ackie is lean and active, not heavy and sluggish. Monitor body condition and reduce feeding frequency if the animal is gaining excess weight. Provide fresh water at all times. Browse our live feeders and frozen feeders.
Enrichment
Ackie Monitors are genuinely intelligent and benefit from enrichment. Rearranging their enclosure occasionally, offering food that requires hunting (never in a bowl), and providing digging opportunities all contribute to a healthier, more active animal. Many Ackies become remarkably tame with consistent, calm interaction.
Breeding
Ackies breed readily in captivity following a winter cooling period of reduced temperatures, shorter days, and reduced feeding. As conditions warm in spring, mating occurs and females lay clutches of 6 to 18 eggs in a deep, moist nesting area. Eggs are typically incubated at around 28 to 30°C and hatch in roughly 90 to 120 days. Breeding should only be attempted by keepers with appropriate licence conditions and the resources to care for hatchlings.
Quick Reference
| Parameter | Target |
|---|---|
| Adult size | 55 to 70 cm |
| Lifespan | 15 to 20 years |
| Enclosure (adult) | 150 x 60 x 75 cm minimum |
| Basking surface | 50 to 60°C (measure with IR gun) |
| Warm ambient | 28 to 32°C |
| Cool end | 25 to 28°C |
| Night | 20 to 22°C |
| UVB | T5 high-output, 10 to 12 hrs/day, replace every 6 to 12 months |
| Substrate depth | 15 to 20 cm minimum |
| Feeding (juvenile) | Daily |
| Feeding (adult) | Every 2 to 3 days |
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If you have questions about high-output basking setups for monitors, our team is always happy to help.
Disclaimer
This guide is provided for general educational purposes only. It is not a substitute for professional veterinary advice. Individual animals vary and outcomes cannot be guaranteed. Always consult a qualified reptile vet for health concerns. A Queensland wildlife keeper's licence is required to purchase and keep Ackie Monitors.
