A University of Queensland PhD student has discovered an ancient and remarkable species of leaf-tailed gecko in a remote area north-west of Townsville, in North Queensland.
Conrad Hoskin, a PhD student in UQ`s School of Life Sciences, has described the new species, known as the Gulbaru gecko (Phyllurus gulbaru) in the Australian Journal of Zoology.
Mr Hoskin has already expressed concern for the new species, which he said under current international conservation criteria warranted an endangered listing.
He said the Gulbaru gecko was a spectacular creature that was prickly and large — about 13cm long — and new to science.
“Like most geckos, it has no eyelids and hence it has to keep moistening its eyes with its tongue,” Mr Hoskin said.
“It is perfectly camouflaged to its rocky environment, with granite-like colourings and so is very hard to find. However, unlike most geckos, it has no pads on its skinny fingers, so it cannot climb windows like the common household geckos can. Instead it has sharp claws for climbing rocks.
“Leaf-tailed geckos are so-called because their tails look like flat leaves, but the Gulbaru gecko`s tail is obviously different, being long and cylindrical.”
In 1998, Mr Hoskin discovered a distinct leaf-tailed gecko, the Mt Elliot gecko (Phyllurus amnicola) in a neighbouring area near Townsville.
In 2001 he was with a UQ group checking skink populations and during a nocturnal search of the area to look for geckos he was confronted by a pair of red eyes glowing in the dark. It was the Gulbaru gecko, an obviously different species which on genetic examination, proved to be more closely related to leaf-tailed geckos from the Mackay area than the Mt Elliot gecko Phyllurus amnicola he previously discovered.
Mr Hoskin said molecular data showed that leaf-tailed geckos represented ancient lineages which could be traced up to 74 million years ago, with closely related species in central Queensland dating to 38 million years ago. The Gulbaru gecko and other leaf-tailed geckos appeared to be Gondwanan, and related to gecko species in New Zealand and New Caledonia.
Only two small sub-populations of the Gulbaru gecko were known to exist, both in rocky rainforest areas surrounded by open eucalypt forests, very little of which is protected.
“It is one of the most narrowly restricted reptile species in Queensland,” he said. "The species is distributed in two sub-populations and the total area occupied is estimated at less than 14 square kilometres. In reality it is probably a lot less than this as within this area it is very patchily distributed across rocky gullies.
“International conservation criteria define endangered species as those occupying an area of less than 500 square kilometers in which there is evidence of a decline in numbers or suitable habitat.
“Only a small fraction of the suitable habitat for the Gulbaru gecko receives some degree of protection in state forest. Our surveys indicate that the species probably occurs in two subpopulations near Townsville separated by an expanse of unsuitable habitat.
“The reduction and fragmentation of patches of suitable habitat by fire poses a threat to the survival of this species. Since this species was discovered, much suitable habitat has already been destroyed by severe burning. The destruction of habitat by unmanaged burning continues to reduce and further fragment the available habitat.”
Mr Hoskin said scientists had largely concentrated on the extensive rainforest of the Wet Tropics but the discovery of the two new gecko species in the small patches of rainforest just to the south of the World Heritage Area in the Townsville region underlined the importance of these localities.
Queensland Museum is keeping a few preserved specimens of the new species for scientific comparison.
Mr Hoskin is also currently describing a new frog and also a new species of reduced-limb lizard from North Queensland. He said these discoveries were of considerable interest as it was rare to discover a new vertebrate species, especially along the populated east coast.
His PhD thesis on rainforest speciation in frogs is being supervised by Associate Professor Hamish McCallum at UQ and Professor Craig Moritz at the University of California at Berkeley.
Mr Hoskin`s work has received support including a $5000 University of Queensland Graduate School Travel Award, an Australian Postgraduate Award, and funding from the National Science Foundation, Cooperative Research Centre for Tropical Rainforest Ecology and Management and the Queensland Museum.
Media: For further information, contact Mr Hoskin (telephone 07 3365 4908, email choskin@zen.uq.edu.au) or Joanne van Zeeland at UQ Communications (telephone 07 3365 2619).
