PREVIEW

The Australian Wildlife Conservancy (AWC) has released its fourth annual Bilby Census results, revealing that populations of the native mammal have “dramatically expanded” in the past twelve months within six surveyed sanctuaries across the country.

Also known as rabbit-bandicoots, or by their Latin name Macrotis, bilbies are desert-dwelling marsupial omnivores averaging 55 centimetres in size – excluding their tails, which are usually around 29 centimetres long.

English invaders to Australia first described two species of bilby – the Greater Bilby and Lesser Bilby – but wiped out the Lesser Bilby by the 1950s.

The Greater Bilby survived but is listed as a vulnerable species.

The AWC described the bilby as “Australia’s answer to the Easter Bunny”, referencing the animal’s characteristically long ears.

Bilbies also share bunnies’ behavioural trait of burrowing, though the two species last shared a common ancestor over 100 million years ago.

AWC works in partnership with six sanctuaries which protect bilbies, including Mt Gibson (in Western Australia), Newhaven (in the Northern Territory), Yookamurra (in South Australia) and Scotia, Pilliga State Conservation Area, and Mallee Cliffs National Park (all in New South Wales).

Together, the sanctuaries have recorded a population of 3,300 bilbies and an increase in burrowing activity.

“At Newhaven, Bilby burrows are completely transforming the landscape,” Wildlife Ecologist Dr Tim Henderson said in a statement. “They’re popping up everywhere, even on our access tracks which can make it a little difficult for us to get around but it’s great to see.”

He continued, “All this burrowing is reinvigorating the landscape, and it’s not just Bilbies which benefit. We sometimes see multiple species using Bilby burrows, including Golden Bandicoots and Burrowing Bettongs. Bilbies will normally dig a single burrow, then Burrowing Bettongs will come in and renovate it into a multi-entrance complex.

“This level of earthworks is incredible.”

The Pilliga sanctuary reported that their bilbies had dispersed from the initial smaller breeding area into their wider fenced area, while Yookamurra reported that their bilby numbers had more than doubled since the end of their drought in 2020.

In 2018-2019, New South Wales experienced its most severe drought in 120 years.

In 2022, 66 bilbies were released inside Newhaven’s 9,450-hectare feral predator-free fenced area on the traditional lands of Ngalia-Warlpiri and Luritja people.

Initially, 10-20 per cent of the site’s motion cameras spotted the bilbies out and about.

However, after 18 months, the area has expanded to 50 per cent.

Tim gushed, “This is great news because it indicates that their population is growing and they’re occupying a lot of the available habitat.”

The Pilliga sanctuary noted a bilby burrowing “frenzy” at their site in the past year.

“The Bilbies with their engineering colleagues, the bettongs, have turned over a lot of soil in their search for food and when digging burrows,” Senior Wildlife Ecologist Dr Vicki Stokes said in a statement. “These activities will improve the ecosystem health of the Pilliga forest over time.”

Bettongs are another vulnerable Australian mammal known for burrowing.

The team has also encountered a number of baby bilbies, with Vicki celebrating, “Two of the female Bilbies had tiny baby Bilbies (called joeys) in their pouches. We’ve also had increasing Bilby activity on motion-sensor cameras across the fenced area, indicating that the population is doing well.”