Mountain dragon, Rankinia diemensis
The mountain dragon is the only species of the dragon family living in Tasmania. It is a relative of frill-necked lizards and the thorny devil. Mountain dragons are egg-laying lizards that feed on ants and other small invertebrates.
Description
Small, rough scales, loose skin, a spiny tail combined with a large, deep head and a squat appearance makes the species unmistakable. Mountain dragons generally have a row of large, paler, diamond shaped markings on either side of the back, often joined to make two irregularly-shaped stripes. Females reach a larger size than males, and have a relatively smaller head. This attractive lizard is occasionally and mistakenly called a "gecko" by locals. The general colour can be grey through to brick red, often matching the environment in which the dragons are found.
Ecology
Like many members of the dragon family, mountain dragons can adjust the tone of their pigments to suit environmental conditions, generally being darker in cooler conditions to absorb more warmth from the sun, becoming paler under warmer conditions to reflect it. These changes occur through concentrating or dispersing pigment in cells in the lizard's skin. These attractive dragons take advantage of warmed rocks as well as direct sunlight to raise and maintain their body temperature. The Mountain dragon eats a variety of insects, including ants. Anecdotal accounts suggest this species may be capable of living over 10 years. Mountain dragons tend to live in dry woodlands and heaths where there is plenty of sunshine. On the mainland this species overwinters beneath large logs.
Breeding
Like all members of the dragon family, mountain dragons lay eggs. The 2-9 eggs measure about 15 mm in length and are laid at the end of a short burrow in sandy soil over spring and summer. There is some evidence to suggest that females are capable of producing more than one clutch of eggs in a season. Upon hatching the juveniles are about 60mm in total length. Small hatchlings emerge in late summer.
Distribution
Northern, eastern and southern Tasmania, and Central Plateau in open vegetation such as coastal heath, grassy woodland or open forest. They have been recorded from Badger, Bruny and Flinders Islands. Mountain dragons occur in southeastern mainland Australia.
Status
Secure, but declining on the urban fringe.
Threats
Domestic and feral cats kill small lizards such as mountain dragons. Changes in fire frequency and the removal of large logs may remove secure overwintering sites for this species.