THE recent discovery of two new gecko species is offering insight into how desert-dwelling reptiles evolve in isolated pockets in arid landscapes.

Known for their ‘sticky feet’, due to microscopic hairs on the pads of their toes, many of Australia’s tree and rock dwelling geckos can be seen clinging precariously to vertical surfaces.

Australia’s desert geckos are quite different. Predominantly ground dwellers, they possess long, often slender, fingers ending in claws, enabling them to move rapidly over short distances in pursuit of prey.

Recent DNA evidence has revealed a new desert gecko species which evolved from one of four families of gecko occurring in Australia – Diplodactylus.

Discovered on the North-west Cape near Exmouth, the Cape Range Gecko (Diplodactylus capensis) is remarkably similar to its neighbour, the Stone Gecko, but DNA evidence indicates the two species are separated by millions of years of evolution.

WA Museum zoologist, Dr Paul Doughty identified the Cape Range Gecko and believes it is a typical case of ‘evolution in isolation’.

“What is fascinating about the Cape Range Gecko is its evolution far from its nearest relatives 600 km away,” Dr Doughty says.

“It only occurs on the Northwest Cape and is characterised by a distinctive broken stripe on its back, larger head and reddish colouration, which matches the colour of the rocks on the Cape Range.

“This region is better known for the Ningaloo Reef and its Whale sharks but we are finding unique new species of lizards in this diverse habitat,” he says.

The second species, the Southern Sandplain Gecko (Lucasium bungabinna) was discovered in the southern deserts in Western and South Australia, north of the Nullarbor Plain.

As a member of the ground-dwelling desert geckos, which generally have reduced sticky toe pads, the Southern Sandplain Gecko is uncommon for the Lucasium genus.

“Distinct from its desert gecko cousins, the Southern sandplain gecko is able to climb spinifex and low bushes.” Dr Doughty says.

“It occurs from the Bungalbin sandplain in WA across the Yellabinna dune fields, extending to the eastern edge of the Eyre Peninsula in SA.”

Research on both species was carried out as part of ongoing projects to identify endemic (exclusively native species) reptiles in Western and South Australia.

The project was funded by a grant from the Australian and Pacific Science Foundation with support from the WA and SA Museums.