Biodiversity Blooming in the Outback

29 November 2012

Fresh back from a two-week stint in the State's North West, our scientists are in awe at the level of biodiversity at an "ecosystem crossroads" in the Gawler Ranges.

Ten of our researchers camped at Hiltaba – a 77,355 hectare property owned by the Nature Foundation – as part of a Bush Blitz program oraganised by the Australian Biological Resources Study (ABRS), Earthwatch and BHP Billiton.

"There are three major ecosystems all converging on the one place," says Senior Researcher in Herpetology, Dr Mark Hutchinson. "You've got the rocky Gawler Ranges; you're very close geographically to the bottom of the Lake Eyre Basin, so salt lake habitats and things like that; and then in the west you've got the Great Victoria Desert sand dune systems, which have their own very distinct group of species. Hiltaba is one patch that has a rare collection of life from all of those ecosystems."

Scientists camped onsite and trekked across the diverse country, setting traps for reptiles and mammals and collecting invertebrates, such as insects, butterflies and moths. Their aim was to take stock of flora and fauna to get a more accurate picture of South Australia's biodiversity and potentially, that of similar ecosystems across state and territory borders. Given that the sheep had previously roamed the property, the scientists were surprised at the abundant life at Hiltaba.

"Before we got there, there was no record of any venomous snakes but we found three different species," says Dr Hutchinson.

Terrestrial Invertebrates Researcher Dr Mark Stevens says "in the first week, people were quite enthusiastic and surprised by all the things we were catching. From one sweep, there were at least 30 species of native bees. In one hour, we caught around 50 species of moth from a light-trap. Across the two weeks, we caught 12 species of butterflies, some of those not known from that area previously with 2 Candilides species found several hundred kilometres to the west from previous records."

The scientists will study their specimens at the South Australian Museum. Some of the specimens collected are unknown and will need to be identified and many likely to be new species.

Our researchers say the health of Hiltaba is evidence the previous owners took care not to damage the ecosystem too much when their stock was grazing. Dr Hutchinson says other landowners can learn from their example.

"You can use these arid zone leases as an agricultural area and you don't have to run them into the ground by overstocking. You can stock them at a level that enables you to make a living and still coexist with a lot of natural diversity."

Hiltaba still faces a pest problem. The Nature Foundation and the Berri football team have helped clear many feral goats on the property. These animals damage plants and interrupt the natural biological relationships.

Dr Stevens says 3000 goats were recently removed but there are still likely to be thousands on the property and will need to be cleared.

"It's quite obvious that the goats have affected the vegetation and of course just the traffic – they share the environment with other animals and the litter and the soils become damaged. It's very important to deal with that problem if you want vegetation to go back to a natural state."

Hiltaba is positively a biodiversity hotspot. Our scientists will work hard to use their specimens to illustrate the complex ecological relationships of the place and help communities better protect Australia's amazing wildlife.