Bilby populations climb across the country

The pint-sized marsupial, which has soft grey fur, long ears and pointed snout, is classified as vulnerable to extinction in the wild.

But it's experiencing a population boom inside a series of predator-free havens, the Australian Wildlife Conservancy says.

The nocturnal forager's numbers have grown from about 1230 animals last year to around 1480 within five protected areas across the country.

AWC protects about 10 per cent of Australia's remaining bilby population, which is estimated at around 10,000 individuals.

Once found as two species before the 1960s, the omnivore inhabited an estimated 70 per cent of the continent before European settlement.

But it's been decimated by feral foxes and cats, and habitat loss, with its range reduced to less than a quarter of that area.

AWC's annual census surveyed sanctuaries north of Perth at Mt Gibson, Yookamurra outside Adelaide and Scotia, Pilliga and Mallee Cliffs in NSW.

Increased rainfall during the second year of La Nina has helped replenish swathes of Australia's arid interior, providing good conditions for breeding.

There's also evidence the uptick in bilby numbers reflects the success of AWC's rewilding program.

Bilbies made a historic return to its 9570-hectare precinct at Mallee Cliffs National Park in southwestern NSW in October 2019.

Prior to the relocation, the mammal had been absent from the area for over a century but the population thrived in its former range, doubling within six months to 108 individuals by July 2020. It currently stands at 116.

Mt Gibson in Western Australia's Wheatbelt joined the fight to save the species in 2016. Between 2016 and 2018, 56 individuals were released inside the 7800-hectare haven.

Bilbies returned to the Pilliga State Conservation Area in northern NSW in late 2018 after being absent from the landscape for more than 100 years.

Sixty were released into the 680-hectare precinct and more than doubled to an estimated 155 animals in late 2021.

"We're expecting the population to continue to grow because conditions in the Pilliga are so good with all the recent rain," ecologist Vicki Stokes said.

"It is such a delight to see all the bilby diggings and burrows as you walk through the forest."

Bilbies are important ecosystem engineers. A single animal can turn over up to 20 tonnes of topsoil in a year as they dig burrows up to three metres long.

They eat a broad diet consisting of insects, seeds, bulbs, fruit and fungi.

Scotia Wildlife Sanctuary in western NSW is home to the largest population of bilbies inside the AWC sanctuaries.

The population within the 8000-hectare site regularly climbs above 1000 animals during boom periods when conditions are optimal.

Bilby numbers have remained steady at South Australia's Yookamurra Wildlife Sanctuary over the last 12 months, with the population estimated at 80 individuals compared to 83 individuals 12 months ago.

AWC expects to protect up to 5000 bilbies within a decade.

Australian Associated Press