General Care Requirements

Monitor lizards vary enormously in adult size, habitat and diet. This guide provides a practical example for the ackie monitor (Varanus acanthurus), a relatively small, active Australian species. It is not a housing or feeding template for savannah monitors, water monitors or tree monitors.

Natural Habitat

Ackies inhabit rocky, seasonally dry landscapes in Australia. Rock crevices, burrows and scattered vegetation provide shelter between feeding and basking periods. Their environment combines hot exposed surfaces with much cooler, more humid retreats.

Housing

Plan for a substantial enclosure despite the species’ relatively modest size. Approximately 150 × 75 × 120 cm is a practical starting recommendation for one adult; additional floor space is beneficial. The enclosure must accommodate deep substrate, climbing structures and safe distances from lighting.

Provide approximately 30–45 cm of diggable soil-based substrate that holds a burrow without collapsing. Install securely supported rockwork, crevices, branches and several sheltered locations. Heavy structures must rest on a stable foundation, not on substrate the monitor can excavate.

Include a readily accessible water bowl and opportunities to search for food. Individual housing avoids the need to manage dominance and breeding pressure. Mature females require suitable deep nesting substrate even when housed without a male.

Temperature, Humidity & Lighting

Provide a broad basking surface around 60–70°C, with cooler air temperatures approximately 24–28°C. These are different measurements: the basking figure is a local surface temperature, not the temperature of the enclosure air or the animal’s body.

Higher surface temperatures are reported in specialist husbandry, but they should not be pursued without an appropriately designed gradient. The monitor must be able to leave the basking area immediately and reach genuinely cooler retreats.

Use infrared measurements for surfaces and digital probes for air and retreat temperatures. Control heating, protect accessible lamps and prevent concentrated hot spots that heat only a small part of the body. Allow a night-time temperature reduction while avoiding excessive chilling.

Provide bright visible light and appropriate UVB across the basking zone, alongside shaded retreats.

The exposed enclosure can be relatively dry, but deeper substrate must retain moisture. Maintain damp, stable burrows without waterlogging the floor. A dry surface is not evidence that the entire substrate should be dried out.

Feeding

Base the diet on varied, appropriately sized insects, including cockroaches, crickets and locusts. Feed and hydrate the insects properly before offering them, and provide calcium and vitamin supplementation suited to the diet and UVB exposure.

Growing juveniles generally need small meals daily. Adults can commonly receive controlled portions every other day, adjusted to body condition and activity.

Rodents and eggs should not replace the insect-based diet. Excessive quantities of energy-dense foods can promote obesity. Distribute feeding opportunities to encourage searching and movement.

Lifespan

Ackie monitors can live for approximately 15 years or longer with appropriate long-term care.

Common Health Challenges

• Obesity: Large meals, energy-dense foods and inadequate activity can cause excessive weight gain.
• Metabolic bone disease: Inadequate calcium or vitamin D provision can compromise skeletal health.
• Dehydration and retained shed: A lack of moist retreats can contribute to dehydration and shedding problems, particularly around digits and the tail.
• Thermal injury: Uncontrolled heat, inaccessible cool areas and direct contact with equipment can cause serious harm.
• Reproductive disorders: Females may develop follicular or egg-laying problems requiring veterinary care.
• Parasites and persistent digestive problems: Weight loss, abnormal faeces or repeated regurgitation warrant investigation.