Red Ackie Monitor
The red ackie is a small monitor lizard from Australia. Its scientific name is Varanus acanthurus, and it is also called the spiny-tailed monitor, ridge-tailed monitor or ackie dwarf monitor. “Red ackies” are a reddish form of this species and are popular with experienced reptile keepers.
Scientific Classification & Quick Facts
| Common name | Red ackie monitor |
| Scientific name | Varanus acanthurus |
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Squamata |
| Family | Varanidae |
| Genus | Varanus |
| Conservation status | Least Concern |
| Type | Reptile; dwarf monitor lizard |
| Diet | Roaches and crickets; pinky mice for adults |
| Habitat | Dry, rocky country; digs burrows |
| Native range | Northern Australia |
| Size | About 70 cm in total length |
| Colours | Dark brown with cream to yellow spots |
| Special feature | Spiny tail with a round cross-section |
What Red Ackies Look Like
Ackies are one of the smaller monitor lizards. Adults usually reach about 60 to 70 cm (24 to 28 inches) long, including the tail. The tail is long, about one and a half to two times the length of the head and body together.
Their backs are dark reddish-brown to almost black, covered with rows of cream, yellow or orange spots, some with dark centers. Red ackies have warmer red and orange tones. The legs and neck often have stripes or lines.
The best-known feature is the tail. It’s round and covered in rings of spiny, keeled scales, which is how the species got its names. When threatened, an ackie may hide in a rock crack and use its spiny tail to block the entrance.
Natural Habitat
Ackies live in the dry, hot parts of northern and western Australia, including Western Australia, the Northern Territory and western Queensland. They are well adapted to arid country.
They like rocky places, such as rocky hills, gorges and outcrops, where they shelter in cracks between rocks and dig burrows under stones and in sandy soil. Inside these burrows, the air stays cooler and more humid than on the surface.
Behavior and Diet in the Wild
Ackies are active during the day and spend a lot of time basking on hot rocks. They are fast, alert hunters that search for food among the rocks.
In the wild they mostly eat insects and other invertebrates, such as grasshoppers, beetles, cockroaches and spiders. They also catch small lizards and occasionally eat small mammals or eggs.
Red Ackies as Pets
Ackies can’t be exported from Australia, so the ones in the pet trade around the world are bred in captivity. They are active, curious lizards that can live 15 to 20 years, so they’re a big commitment and best for experienced keepers. Kids should always have an adult in charge of care.
Housing
Ackies use every bit of space they’re given. A single adult needs an enclosure of at least 4 feet long by 2 feet deep by 2 feet tall (about 120 x 60 x 60 cm), and bigger is better, especially for a pair. The enclosure must be strong and escape-proof, and it should hold humidity well, so solid sides with modest ventilation work better than an open screen cage.
Substrate
Because ackies love to dig, they need a deep layer of substrate, ideally a foot (30 cm) or more. A mix of clean topsoil and sand works well. Keep it slightly damp so that burrows hold their shape. Humid burrows also help ackies shed their skin properly.
Make sure soil is free of pesticides and fertilizers, and remove sharp stones. Very young ackies are sometimes kept on paper towels for a short time so keepers can check their eating and droppings.
Heat and Light
Ackies come from one of the hottest places on Earth and need a very hot basking spot. Keepers often stack flat slabs of rock or tile with gaps between them, so the lizard can choose spots closer to or farther from the heat lamp. The hottest surface right under the lamp is often kept around 130 to 150°F (54 to 66°C).
The rest of the enclosure should be much cooler, about 75 to 80°F (24 to 27°C) at the cool end, with a warm middle area. This range lets the ackie move around to control its body temperature. They also need UVB lighting during the day and darkness at night. Use thermostats and a good thermometer to check temperatures.
Humidity
The air in the enclosure is usually kept fairly dry, around 40 to 60 percent humidity, while the soil deeper down stays moist. Watch how your ackie behaves and adjust if it seems stressed, has trouble shedding or always avoids one area.
Feeding
Feeding time is one of the most fun parts of keeping ackies. They chase their food with lots of energy and soon learn who brings it, often getting excited when their keeper walks into the room.
Their main diet should be insects, such as roaches, crickets and other feeder insects. Dust the insects with a calcium supplement. Adults can have an occasional pinky mouse as a treat, but too many rodents can make them overweight. Always provide a shallow dish of clean water.
Handling
Ackies are tough, hardy lizards. When young they can be jumpy, but with gentle, regular handling, many become quite tame and calm. Give a new ackie time to settle before handling, keep sessions short at first, and support its body when you pick it up. Many keepers enjoy their bold, curious personalities.
Fun Facts
- Monitor lizards, including ackies, flick their forked tongues to “taste” the air, just like snakes.
- Ackies are related to the much larger Komodo dragon.
- Females lay their eggs deep in burrows, where the temperature and moisture stay steady.
Red ackie monitor FAQs
Where do ackie monitors come from?
They come from northern Australia, where they live in dry, rocky areas. They dig burrows.
How big do ackie monitors get?
An average ackie monitor reaches about 70 cm in total length, and its tail is longer than its body and head.
What do ackie monitors eat?
They eat insects such as roaches and crickets, and adults can have pinky mice. They enjoy chasing their prey.
Why is it called the spiny-tailed monitor?
Its tail is covered with spiny scales and is round when cut across. It is also called the ridge-tailed monitor or ackie dwarf monitor.
Are ackie monitors easy to tame?
Yes, once they get used to a keeper. They are robust and enjoy company after settling in. Regular feeding and patient handling help them trust you.
Randi Jones is the owner and founder of the Nature Gift Store, an online retailer specializing in nature-themed gifts, educational science projects, live animal nature kits and real butterfly artwork. A biology graduate who fell in love with insects, she founded the company in 2001 to make active learning about nature fun, accessible and engaging for children and adults. Her store offers real butterfly frames, home and garden decor and educational live animal kits, including ant farms, worm farms, tadpoles, ladybugs and hermit crabs, and she runs a bug museum in Washington featuring live animals like Eddie the Iguana alongside other reptiles and insects.
