Spiny-tailed monitor — Care Sheet & Morphs

Husbandry requirements

Spiny-tailed monitor — origin: Northern and western Australia: arid, rocky areas (outcrops, scree, dry savannahs)..

Terrarium temperature gradient

Night min20 °C

Cool side24–28 °C

Warm side32–40 °C

Basking spot60–70 °C

A heliophilic species requiring a REAL, very intense hot spot: SURFACE temperature of the basking spot (rock) of 60-70 °C, to be measured with an infrared thermometer. Achieved with a cluster of reflector halogen bulbs, never with a heat mat. A strong thermal gradient is essential: ambient warm side 32-40 °C, cool side 24-28 °C. Lamps completely off at night, a drop to ~20 °C tolerated and beneficial.

Enclosure (adult)

180 × 90 × 60 cm

Terrestrial/saxicolous desert-type terrarium: very large floor area, stable rock stacks and deep substrate for burrowing.

Minimum dimensions for a single adult; bigger is always better. Floor area takes precedence over height. Provide a deep substrate (30-60 cm) for burrows, multiple hides and firmly wedged rocks (never placed on the loose substrate, risk of collapse/crushing). Individual keeping is recommended outside of breeding.

Humidity

40–60 %

Generally dry conditions, but the deep layers of the substrate and a humid hide must remain slightly moist: this burrow microclimate is essential for good hydration, correct sheds and egg-laying by females. Good ventilation is mandatory.

Substrate

Mix of fertiliser-free garden soil / sand (loam)Untreated topsoil mixed with sandCoconut fibre mixed with soil

A deep substrate (30-60 cm) able to hold a burrow without collapsing, hence the soil/sand mix slightly moistened at depth and dry at the surface. Avoid pure sand (risk of impaction and unstable burrows).

UVB

Recommended

Recommended and beneficial: a high-intensity UVB tube (T5 HO 10-12%) placed above the basking zone, for a UVI of about 4-6 at the back level. Replace the bulb every 12 months even if it still lights up.

Water source

Always available

A dish of fresh, clean water available at all times; cleaned regularly.

Origin

Varanidae

Northern and western Australia: arid, rocky areas (outcrops, scree, dry savannahs).

Feeding & health

Diet

Insectivore (mainly) / Carnivore — Crickets, roaches (Dubia), worms; occasionally a pinky mouse or lean turkey in small quantity.

A base of varied, well-fed insects (gut-loaded) and dusted with calcium (+ D3 depending on UVB). Very PRONE TO OBESITY if rodents/fatty proteins are given too often: reserve vertebrate prey for occasional use. Feed juveniles daily, adults 3-4 times a week while monitoring their body condition.

Breeding

Oviparous

Clutch 5–15 eggs/young. Can produce several clutches per year. Provide a deep, humid and loose egg-laying site. Artificial incubation typically around 28-30 °C for ~90-120 days (duration varies with temperature). Captive-bred stock is widely available and to be preferred.

Health watch points

Obesity (excess of fatty prey/rodents) and hepatic steatosis
Osteodystrophy / metabolic bone disease (calcium deficiency or insufficient UVB)
Internal parasitism, especially in individuals of dubious origin
Thermal burns (contact with a poorly protected heat source)
Gout and kidney damage linked to dehydration or an excess of protein

Morphs & genetics

Registry of 0 documented gene for Spiny-tailed monitor.

Frequently asked questions

Answers to the most common questions about keeping the spiny-tailed monitor.

What is the adult size of the spiny-tailed monitor?▾

The Ackie monitor reaches 50 to 70 cm long as an adult, tail included, with the tail making up more than half the body. It is one of the smallest monitors available in the hobby, a size far easier to manage than a large monitor.

What terrarium is needed for this species?▾

Provide a terrestrial, saxicolous desert-type terrarium of at least 180 x 90 x 60 cm for a single adult, bearing in mind that bigger is always better. Floor area matters more than height: this monitor needs stable rock stacks and, above all, a deep substrate, 30 to 60 cm, to dig its own burrows. Individual keeping is recommended outside of the breeding periods.

How do you achieve the basking spot it needs?▾

The spiny-tailed monitor is a great heat lover: it needs a basking surface between 60 and 70 °C, measured with an infrared thermometer, achieved with a cluster of reflector halogen bulbs, never with a heat mat. The warm ambient side should stay between 32 and 40 °C, the cool side between 24 and 28 °C, with a complete switch-off at night and a drop tolerated down to 20 °C.

Is UVB essential for this monitor?▾

It is strongly recommended and beneficial: a powerful UVB tube, of the T5 HO 10-12 % type, placed above the basking zone, aiming for a UVI of about 4 to 6 at back level. Replace the bulb every 12 months even if it still lights normally.

What substrate and humidity for this burrowing monitor?▾

Ambient humidity stays moderate, between 40 and 60 %, but the deep layers of the substrate must remain slightly moist to create a genuine burrow microclimate, essential for hydration, sheds and the females' egg-laying. Use a soil-and-sand mix of the loam type, or coconut fibre blended with soil, avoiding pure sand, which collapses and exposes the animal to impaction.

What should it be fed and how often?▾

It is above all an insectivore, fed on crickets, Dubia roaches and well-fed worms dusted with calcium, with only the occasional pinky mouse or a little lean turkey. It is very prone to obesity if fatty prey is multiplied: feed juveniles daily, but limit adults to 3-4 meals per week while monitoring their body condition.

Does it need permanent access to water?▾

Yes, a dish of fresh, clean water must remain available at all times, to be cleaned regularly.

How long does an Ackie monitor live?▾

Its lifespan is around 15 to 20 years in captivity if the diet is kept in check, with some individuals even exceeding that mark. Conversely, an excess of fatty food and the resulting obesity clearly shorten its life expectancy: it is a long commitment that demands dietary discipline from the outset.

Is this monitor easy to handle?▾

This is precisely one of its great assets: very intelligent, curious and active, it can become remarkably familiar, almost puppy tame, with regular, gentle handling. Its bite nonetheless remains powerful and should be disinfected if it happens: trust is built gradually.

Is the spiny-tailed monitor suitable for a beginner?▾

It is rated as an intermediate-level species: managing such an intense basking spot and a deep burrowing substrate requires a minimum of experience. It is also listed in CITES Appendix II: insist on legal transfer documentation and favour captive-bred specimens, as Australia bans the export of its wildlife.

What health problems are the most common in this species?▾

Obesity and hepatic lipidosis top the list, followed by metabolic bone disease in the event of calcium deficiency or insufficient UVB, internal parasitoses in specimens of dubious origin, burns from contact with a poorly protected heat source, and gout linked to dehydration or an excess of protein.

How does breeding proceed in this species?▾

The female can produce several clutches of 5 to 15 eggs per year, provided she has a deep, moist and loose laying site. Artificial incubation is generally done at around 28-30 °C for about 90 to 120 days, a duration that varies according to the chosen temperature.

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