Thirty-three giant burrowing frogs were radio-tracked over more than two years in forests on the NSW south coast. The research found that the frogs spent the majority of their time burrowed under the ground, travelling over a relatively small area. Photos Frank Lemckert/Forests NSW Image Library

Some might suggest the giant burrowing frog is not the most attractive of frogs. It’s not green. It has black warts. And sometimes the warts have spines. But for Newcastle University PhD student, Trent Penman, the frog has a certain attraction that has kept him focused on their lives and activities for the past five years.

Chocolate brown in colour and close to ten centimetres long, the giant burrowing frog (Heleioporus australiacus) is a threatened species found along the Australian east coast from Walhalla in Victoria through to Singleton in New South Wales.

“I started studying these cryptic frogs in State forests around Eden in 2001,” PhD student, Trent Penman, said. “Usually only seen on roads after heavy rainfall, and often considerable distances from creeks, my study was aimed at uncovering more of these frogs and having a thorough look at their biology.”

Trent worked closely with operational staff from Forests NSW and also with NSW Department of Primary Industries senior research scientist and herpetologist, Frank Lemckert.

Thirty-three giant burrowing frogs were radio-tracked over more than two years in Broadwater State Forest, while Trent kept an eye on other frogs in national parks and private lands, as well as in other State forests within the region.

“We found the frogs spent most of their time burrowed between one and 30 centimetres under the ground, at considerable distances from their breeding sites,” Trent said.

“Each frog appeared to have its own small territory ranging in size from 400 to 1000 square metres – about the size of a suburban house block.

“Within these territories, the frogs have a series of burrows that they re-use. This contrasted with the long-held belief that the frogs travelled widely through the forest.”

And as viewers of television wildlife documentaries would know, nature is often cruel. Some of Trent’s tracked frogs did die – in the mouths of red-bellied black snakes or kookaburras.

“In fact, we x-rayed a red-bellied black snake that had eaten one of our radiotracked frogs, and found two more in its belly,” Trent said. “This surprised us a bit, but shows how dangerous life can be for a frog.”

Armed with new scientific knowledge and data from the study, local land managers joined together to develop a management plan for giant burrowing frogs in the south east forests.

“We worked with NSW Department of Environment and Conservation to develop a plan to ensure giant burrowing frogs would continue to populate the State forests of the region,” Forests NSW Edenbased ecologist, Chris Slade, said.

“The plan identifies key population hot spots and places them in ‘population protection zones’ of between 290 and 890 hectares.

“Timber harvesting operations are excluded from these zones, and fire management activities are also carefully planned to ensure that human disturbances should not lead to long-term declines in numbers until such time that further research to determine the impacts of logging and burning is undertaken.

“A key aspect of the new species management plan is to uncover more facts about the frogs such as how these frogs really do cope with timber harvesting,” Chris said. “We will continue to monitor these populations over time.”

This article appears in the Spring 2006 edition of Bush Telegraph Magazine.