Care Sheet: Mountain Heath Dragon (Rankinia diemensis)

Last update: 22 March, 2023

This care sheet has been created using a variety of online sources (credited) combined with personal experience. If you believe there are factual inaccuracies, please let me know.

Natural Environment

Mountain Heath Dragons, or Mountain Dragons as they’re also known, inhabit primarily dry, rocky woodland areas across south eastern Australia, ranging from mid-New South Wales to Tasmania. They mainly keep low to the ground, foraging and sheltering amongst the heaths of Australia’s dry sclerophyll forests, particularly in more mountainous regions, with ready access to rocky outcroppings for basking and warmth. They do climb for better vantage points, particularly around mating seasons, but rarely climb very high.

Size

Their size can range from 49 – 66 mm for males and 56 – 82 mm for females (snout to vent), with tail length 82 – 113 mm for males and 82 – 137 mm for females 1.

Longevity

Data seems to vary, speculatively somewhere from 2 – 4 years in the wild. Up to 7 years has been observed in captivity.

Handling

Quite tolerant of handling, though can be fast movers when motivated. It is important to support the limbs and body of the lizard when handling, being cautious not to apply undue pressure to their sensitive sides and underbellies.

They are physically capable of biting, but it’s a low risk and more likely to happen by mistake than a deliberate action. Their primary self-defence is camouflage and fleeing.

While it’s preferable not to grab a lizard of any kind by the tail, Mountain Dragons do not perform autotomy.

Husbandry

Enclosure

Coming soon.

Substrate

Coming soon.

Furnishings

Coming soon.

Lighting

Coming soon.

Temperature

Coming soon.

Sun

Coming soon.

Diet

Insectivores. Most sources indicate primarily ants (though not what kind), and other small invertebrates. In captivity they happily eat crickets, mealworms, wood cockroaches, and black soldier fly larvae. They can eat small amounts of some vegetation, such as shredded carrot, but it’s not preferred 2. Ideally their food will be no bigger than the distance between their eyes.

Brumation

In the wild, Mountain Dragons enter a state of brumation for the Winter months. The males emerge from brumation in early Spring, a couple of weeks before females who emerge in late Spring 1. One of the primary risk factors for offspring survival, particularly from late season clutches, is lack of time to store energy reserves before entering this state. In captivity, it’s important to either ensure that hatchlings are well enough fed prior to brumation that they can last through the period, or prevent them entering this dormant state for the first year of life by maintaining temperatures and light cycles appropriately. Once they have entered this dormant state, it’s difficult to bring them back out of it enough and in time to address a lack of nourishment.

Breeding

Oviparous. Main breeding activity tends to occur from late October to early November, with females able to lay their first clutch around November to mid-December. Moulting usually occurs after breeding is over. A second breeding activity period may then occur from around December to mid-January, which may result in a second clutch (note that observations show a second breeding is not necessary for females to produce a second clutch, as they are able to store sperm). Clutches can be anywhere from 2 to 11 eggs, with higher numbers associated with larger females. If a second clutch occurs there are usually fewer, but larger, eggs (possibly also larger hatchlings? Speculative) 1.

Gravid females will often start digging “test” burrows for several days before finally digging their nest burrow and laying their eggs, which they do by digging down at an angle, then turning around to lay, and finally covering the eggs 1.

Egg incubation time in nature can range from 72 to 106 days (average 92 days), with nest temperatures ranging from 5.6 – 39.5 °C (average 19.2 °C). Hatching success in these conditions can be 80%+, with warmer nests having better overall hatchling survival as shorter gestation times allow for longer basking and resource gathering prior to their first brumation. Temperature does not determine hatchling sex 1.

Sexing

Mountain Heath Dragons are sexually dimorphic in terms of size, with females generally being larger than males. You can also visually identify males by subtle testicular lumps on the underside of the base of their tail. These can be further confirmed by holding the animal and shining a torch against the side of the tail’s base, allowing you to see two darkened areas where the testes are 2. These lumps and darkened areas will be absent for females.

References

  1. “Reproductive ecology of the Mountain Dragon, Rankinia (Tympanocryptis) diemensis (Reptilia: Squamata: Agamidae) in Tasmania” – https://eprints.utas.edu.au/13370/
  2. “Mountain Dragon | Species Special” – https://www.youtube.com/watch?v=dmBsjx5P04I