Inside the wild training zone where endangered bilbies are learning to survive
More than 500 endangered marsupials have reclaimed their desert home, as a revolutionary conservation program teaches them to outsmart cats and foxes.
Endangered western quolls, bilbies and golden bandicoots are reclaiming the central Australian desert, fighting back against introduced predators that have driven them to the brink of extinction.
The battleground is a parched corner of red dirt in outback NSW, sandwiched between the famed dingo fence and wire cordons to hold feral cats and foxes at bay.
While the penetration of marauding carnivores is well below that outside the safe-ish zone – only a zoo is truly secure for the pint-sized marsupials – these timid desert dwellers must also sharpen their own survival skills, buying time for the saving grace of natural selection to kick in.
To date, 305 bilbies, 234 golden bandicoots and 51 western quolls have been released into the Wild Training Zone of Sturt National Park under the conservation effort, backed by the University of NSW, the state government and Taronga Conservation Society.
They are breeding there at an encouraging clip. In fact, the program has proved so successful the bandicoot and bilby populations exceeded the notional carrying capacity of the reserve’s northern enclosure, forcing some animals to be trapped and released elsewhere behind the fences.
Soon, scientists hope to start seeding colonies in the wild, where they will fend for themselves without human assistance. This could be a template for reintroducing other at-risk native fauna to the continent’s vast, arid heartland.
“We are showing that a holistic approach to ecosystem restoration can really kick goals,” said Richard Kingsford, UNSW’s Wild Deserts Project leader.
“You can’t just ‘set and forget’. You have to manage whole ecosystems to deliver results, including the feral species and reintroduced species which can become too numerous.”
Of course, the news is not so positive for the cats and foxes that arrived with the first Europeans and went to town on what Professor Kingsford calls “bite sized” indigenous wildlife. Cats are estimated to kill more than three billion native animals each year.
The 100sq km training zone near Cameron Corner, where the borders of NSW, Queensland and South Australia meet 1300km northwest of Sydney, was selected in part because the relatively low presence of feral predators gave the reintroduced marsupials a fighting chance.
The odds were further evened by a cull of cats and foxes. Shooters were sent in and poison traps set – although the cats turned out to be a tricky proposition.
As Professor Kingsford puts it, they’re “live prey” hunters that tend to turn their noses up at baits. Instead, AI-powered grooming traps can identify a passing cat or fox and spray it with a specifically engineered toxic gel, ingested orally when the targeted creature performs its ablutions.
The aim is to reduce the density to no more than three per 10sq km in the Wild Training Zone – a tenth of what would be encountered outside.
The marsupials also have to do their bit. An ongoing presence of predators is part of the plan, weeding out the careless or lazy in mother nature’s pitiless, time-honoured method.
“If you’ve got a bilby that’s not particularly vigilant, the hard biological fact is that it’s probably not going to get to pass on those genes if there are cats in there,” Professor Kingsford said. “That’s the bigger picture we’re looking at; you want vigilant animals to survive and thrive and let natural selection take its course.”
What works for the quolls, bilbies and bandicoots in the training zone today could help in the future revive other endangered marsupials including the kangaroo-like brush-tailed bettong, the insect-eating numbat and black-flanked rock wallaby, all victims of feral cat and fox intrusion.
But the next step of rebuilding numbers outside the wire would be challenging, cautioned researcher Katherine Moseby, the deputy director of UNSW’s Centre for Ecosystem Science.
“Releasing threatened mammals beyond fences is extremely difficult as many are highly susceptible to cat predation,” Professor Moseby said.
“By managing cat densities at very low levels we have seen that some native species can learn and adapt to living with feral cats.”
Ecologist Reece Pedler, the Wild Deserts Project manager, said the surge in golden bandicoot and bilby numbers in the northern Thipa section of the reserve was a good problem to have.
He said: “We need to manage populations sustainably, whether in a zoo or in a safe haven. Our safety valve was releasing them into the Wild Training Zone where they are flourishing so far.”
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