The Dog Fence

Link to ABC's Ockham's Razor or read below

The Dog Fence


Transcript From the ABC's Ockham's Razor

Well there have been hundreds of contributors to Ockham's Razor over this 20 years, the most prolific was Professor Anthony Barnett, who died last year. This week our guest turns out to be James Woodford, author of many excellent books about Australia's natural history, from the Wollemi Pine, to the Hairy Nosed Wombat. This time he talks about The Dog Fence.

James.

James Woodford: With its neat, new streets and modern homes, Roxby Downs reminded me of Canberra coated with a dusting of paprika. The only reason for this city's existence is the Olympic Dam Mine, and I expected to drive into a rusty town peopled by hard-bitten old miners. Instead, I was in a place full of young families. It was the closest I felt to home since I had left Sydney a fortnight earlier, to begin my journey along the 5,400 kilometre long Wild Dog Fence. I headed straight for the mall in the town centre. An hour after worrying that I was going to bog myself on a sand dune in the middle of nowhere, I was ordering a banana smoothie at a Wendy's franchise in the main drag of town. As I had driven into Roxby Downs I saw sand dunes hard up against the backyard fences of quarter acre blocks with emerald-green lawns.

I hoped to meet with a team of young scientists based here who are working to protect Australian fauna. In 1997 the South Australian National Parks and Wildlife Service, the University of Adelaide, volunteers and Western Mining Corporation erected a cat, rabbit, dingo and fox proof fence around 60 square kilometres of this sand dune country. Slowly the native animals that once lived there were reintroduced. More than 10 kilometres of the boundary of the sanctuary, called the Arid Recovery Reserve, is made up of the Dog Fence, and I wanted to see how it could be used as a tool for conservation.

This is the largest area on mainland Australia from which rabbits have been removed. Once inside a feral-proof fence, native creatures are safe from predation and competition, and often breed explosively. Tragically though, sanctuaries like this are becoming the only place to see creatures such as bilbies, bettongs and bandicoots. Apart from kangaroos and emus, virtually all other large native life in central Australia has been eradicated from vast areas of their former ranges. But feral-proof fences only buy us some time. Unless noxious predators are exterminated and habitat degradation is reversed then the continent's ecosystems will become as bereft as the abandoned Cold War era rocket range buildings I had seen a few days earlier at Mount Eba Station, back along the Dog Fence.

I sat in my car, waiting for Peter Paisley, a Western Mining Corporation employee, who over the phone offered me the three things I most wanted: dinner, a shower and a place to sleep. Paisley is a big, friendly guy, so tall that he had to refit his bathroom mirror nearly a foot higher to see his reflection. He is the double of one of my best friends so I instantly felt as though I had found not only a home for a night but a mate as well. After a three-course vegetarian meal Paisley took me back to the mall so I could meet local roo shooter, Lindsay King.

King was sitting in near darkness on a park bench on a traffic island in the town centre, devouring an enormous hamburger and drinking flavoured milk. His day was just beginning. As the night cooled, he would head out for several hours of kangaroo shooting. He would gut his catch out of town before dawn, providing a boon for local scavengers, and then send the chilled carcases off to Adelaide to be sold for human consumption.

Roo shooters are another nocturnal creature of the outback and the Dog Fence is one of their favourite haunts. Most pastoral stations have at least one full-time roo shooter. At night two-way radios come alive as hunters discuss the shooting. It is a lonely and bloody existence, and when Paisley told King about plans to radio-collar half a dozen rabbits outside the sanctuary so we could monitor their movements, the roo shooter looked dumbstruck.

We arranged to talk over the radio through the evening and then climbed in Paisley's four-wheel-drive and headed into the desert.

Thirty minutes later I was back out on the Dog Fence with the sanctuary scientists. Paisley was armed with a .22 rifle and I had a fishing net. We used a spotlight from the back of the ute to search for rabbits outside the reserve. As soon as we spotted one, the vehicle came to a jolting halt. Paisley raised his rifle and fired a bullet between the ears of the pest to stun it. Two of us jumped off and sped through the scrub as the rabbit bolted. The first rule of the net is that you aim it in front of the animal. Rabbit numbers are at a historic low, largely due to calicivirus, and it was not until 1.30 am that we had caught and collared the six animals that Anthony Pieck needed for his study. We had also seen three feral cats outside the sanctuary fence, and Paisley shot one as it fled.

Up the road from the sanctuary, near William Creek, sits the Cat Tree. Here the public and shooters hang dead feral cats from an old mulga, and at any time there may be dozens of the stinking carcases dangling like macabre Christmas decorations. Mummified cats even hang from signs on the road into Roxby.

I was desperately tired but Paisley wanted to show me inside the sanctuary at night-time. The young scientists drove back to Roxby while Paisley and I opened Jurassic Park-like gates into the reserve and entered a marsupial world that would make any cat-lover ashamed. My first impression was that there was a marsupial mice plague - they had not been reintroduced into the area but had taken advantage of the sanctuary's safety to explode in numbers and they hopped across our path at speed. The mesh that protects the reserve is three centimetres in diameter, which is small enough to keep even rabbit kittens out but not to prevent the mice from leaving. Paisley had a gecko to release and we saw two bilbies and two burrowing bettongs.

On the way back to Roxby, Paisley radioed through to King and asked him how his shooting was going. 'I've only got 40 so far', was the reply. He told Paisley he was heading out near the Dog Fence to find a mob and asked whether I wanted to join him. But having been out on the Dog Fence since 6 that morning, all I wanted to do was stop for a few hours and give my brain and body rest. At 3am I finally fell asleep on my ground mat on a slab of concrete near Paisley's carport. At 6am the scientists headed back out to the sanctuary. I planned to meet them at 9, which gave me enough time to refuel and organise my gear for the next stretch of the Dog Fence.

The scientists were on quad bikes at the base of a six-metre high sand dune, preparing their gear and showing no signs of sleep deprivation. Over 800 species of plants are known to grow in this region and the sand ridge we were climbing that morning was covered in cane grass, hop bush and sandhill wattle. The vegetation was so thick that when my hat blew away it took me nearly half an hour to find it. The sand dunes themselves are a thriving ecosystem and house a strange amphibian, the trilling frog (Neobatrachus centralis) which lives most of its life beneath the dune's surface.

To be a frog in the desert is to be a creature of enormous patience, for rainfall fails to reach the average of 166 millimetres nearly two years out of three. It is possible that these creatures live in excess of thirteen years, feeding only three or four times a year. In severe periods of drought they feed only once every few years and sometimes get one chance in a decade to breed. In 1997, near Tibooburra and after heavy rains, I saw trilling frogs in such immense numbers that it was almost impossible not to step on them. Their tadpoles filled puddles in little black wriggling clouds. Trilling frog tadpoles can metamorphose within 17 days, pumping the same hormone through their systems that induces premature births in humans. Snakes, foxes and cats are all known to feed on the adult frogs. In turn, the amphibians eat as many as 13 different types of ants, as well as termites, spiders, beetles and each other.

After rain back in October 2001, the scientists marked where seven trilling frogs were buried to find out more about what they do underground. Every few months since, the frogs have been carefully excavated to measure their depth below the surface and their weight. There is no easy way to dig up a trilling frog, though a long arm helps. After 20 minutes or more of taking it in turns digging with one of the scientists, Jude Carter, she produced a tiny frog the size of a 50-cent piece, with membranes over its nose and mouth. It had a plastic, heavy, cold feel of a miniature, used, disposable nappy. The one we found was at a depth of 1.12 metres and measures 3.8 centimetres in length. A sand dune would never seem the same to me again; what other strange creatures were underneath our feet? There must be millions of these frogs waiting for the next downpour. Peter Paisley's colleague, John Read, estimates a conservative minimum of 200 individuals per hectare around Roxby Downs, making them the most abundant vertebrate in the area. The frogs are handled for as short a period as possible then carefully put back in their holes and reburied. It was time for me to move on and I wondered what I would find next along the Dog Fence

Bill