BY JOSEPH LEW

At first glance, it is understandable why the bilby with its curious appearance – a pronounced snout, conspicuously large ears and 48 razor-sharp teeth – has a place in Aboriginal folklore.

It has been woven into Dreamtime through the Walmajarri story of Nyarlku, who stole all the pearl shells from Paraku Lake, and burrowed across the desert to the west Kimberly coast.

But unlike the Bunyip or the Dirawong, the bilby is anything but a myth.

Known by various names in different indigenous languages –Ninu, Mankarr, Walpajirri, Pingki-tawutawu – the iconic marsupial pre-dates human habitation in Australia, with fossil records dating back 15 million years.

Once found everywhere west of the great dividing range, the bilby inhabited 70 per cent of the Australian mainland.

However, the introduction of feral predators, changing fire patterns and habitat loss following European colonisation has driven the species to mass decline – leaving them to occupy just 20 per cent of their former range. With a remaining population of less than 10,000, the bilby is now categorised as nationally vulnerable.

“There were two types of bilbies once, the lesser bilby and the greater bilby,” Sara Mansfield of the Save the Bilby Fund says.

“The lesser bilby became extinct in the 1950s so we just have Macrotis lagotis now.”

Bilbies are known as ecosystem engineers. Their heavily-built forelimbs and stoutly built toes equip them with substantial burrowing capabilities. In fact, a single bilby can turn over 20,000 kilograms of topsoil per year.

Each individual bilby can dig up to 12 burrows; the process of which has a number of ecological benefits, amongst them, promoting seed germination, soil aeration and increasing soil carbon.

In addition the burrows, which consist of a sharp initial descent followed by downwards spirals and twists, also act like compost bins accumulating organic material and increasing soil-enrichment and fertility.

The ecological significance of this unique creature does not stop there. A three-year camera monitoring project in the West Kimberley region revealed more than 45 other animal species have been sighted using bilby burrows for temporary or permanent shelter. Many of which – such as the northern quoll and the dusky hopping mouse – are listed as threatened under the Threatened Species Conservation Act.

Save the Bilby Fund was established in 1999 and has one singular aim: to save the native marsupial from extinction. The national charity operates several projects across Australia which serve to deliver the National Recovery Plan for the greater bilby.

One such project is the Charleville Bilby Experience, a tourism outlet and breeding facility which allows people to see bilbies up-close in a nocturnal house.

Ms Mansfield, who is one of only four employees at the fund, says when people come face-to-face with the quirky creatures, they invariably fall in love.

“They are kind of weird looking, but they are just cute and adorable,” she says.

“They capture people’s imaginations.”

However, the main project the fund operates is located 11 hours drive west of Brisbane, in Currawinya National Park.

Inside the park sits a 25km squared predator-proof enclosure built by the Save the Bilby Fund under agreement with the Queensland government and in consultation with the local Budjiti people, who protect the local bilby population from predators such as feral cats and foxes.

“Feral cats have decimated everything,” Ms Mansfield says.

“Because they’re not native, bilbies haven’t evolved to deal with them – feral cats can see at night, they can cover long distances and they are a ferocious and effective killer of native wildlife.

"A bilby has got no chance against them.”

In 2019, 22 captive-bred bilbies were released into the enclosure, and in a little over a year, that number has skyrocketed up to 80 individuals.

Bilbies are prolific non-seasonal breeders and have one of the shortest mammalian gestation periods at only 12-14 days.
“We’re on our second generation of pouch young,” Ms Mansfield says.

“The 24 we released last year, those females have had two or three litters and those first litters have had litters of their own.

“They’ve just been bilbying and doing really well,” she laughs.

Meanwhile, in the scorching deserts of Western Australia, Dr Anja Skroblin, a post-doctoral research fellow at the University of Melbourne, has spent the past two years working closely with Martu rangers to monitor local bilby populations.

“It’s quite interesting at the moment when we look at where the Greater Bilby still exists,” the wildlife ecologist says.

“The last estimate that some of my fellow scientists made was that about 70 or 80 per cent of the remaining area where bilbies live are on indigenous land – areas that aboriginal Australians own and manage.”

Monitoring practices provide rangers with the knowledge to best look after bilby populations.

In the longer term, monitoring reveals patterns and trajectories in population data, provides an understanding of the causes of population decline and signals when stressors such as rabbits – which are known to compete with bilbies for habitat – should be removed.

Previously, Martu rangers have been using two hectare plot monitoring, a traditional method which involves identifying and tracking animal signs to determine the movement patterns, and location range of certain species.

However, this method did not particularly suit what the rangers wanted to achieve, so Dr Skroblin designed a new monitoring system which combines western scientific techniques, such as digital data recording, with the indigenous ecological knowledge of the Martu people.

“It brings in information about fire and fire history using Martu terminology, information about the bilby foods and human foods – that are important indicators of country health,” Dr Skroblin says.

“We’re recording a lot of information which is important to indigenous people using their terms and in the way that they would define the country, but using ways to capture information or record data that comes from western technology.”

Dr Skroblin says there is a lot of opportunity out there for these cross-cultural collaborations, but rather than take control of the narrative, western conservation efforts should support and listen to indigenous people who have been managing the land for the past 60,000 years.

“I’m very much of the philosophy that many indigenous peoples have the knowledge that they need in order to manage their own country,” Skroblin says.

“No one knows those areas better than the countrymen and women that live there and are connected to it.”

“[These projects] have to happen in a way that indigenous people maintain power and direction over their own knowledge and their own priorities in the way that they want to manage their country.”