Populations of Australia’s home-grown alternative to the Easter Bunny are growing.

Recent Australian Wildlife Conservancy (AWC) surveys have confirmed that populations of Bilbies, are experiencing a boom within five protected sites, including the conservation area located in the Pilliga Forest.  

As a result of the annual Bilby Census, the overall estimated population at the AWC sanctuaries is at least 3,315, more than double the 1,480 estimated individuals in 2022 and 1,230 in 2021. 

The AWC says that the generous rainfall across most of Australia replenished the landscape and provided good conditions for breeding. 

Dr John Kanowski, AWC Chief Science Officer has welcomed the increase in the overall Bilby population, saying it reiterates AWC’s position as a global leader in successful threatened species reintroductions. 

“The Greater Bilby once occurred across 70% of mainland Australia, and sadly, is now only found within some 20% of its former range,” said Dr Kanowski. “This decline represents the loss of our natural heritage, the loss of cultural heritage for Indigenous people, and the disruption of important ecological processes. As ‘ecosystem engineers,’ Bilbies turn over several tonnes of soil per annum to create fertile pockets and perfect germination conditions for plants.  

“Through fenced refuges, such as those established by AWC, we have been able to return the Bilby to six ecosystems from which they’ve become extinct and provide them with safe environments in which they can safely breed and fertilise their numbers.

“Re-establishing the species across its former range is also important for maintaining long-term adaptive potential.”

During surveys over the last year, ecologists were thrilled to encounter several juveniles and pouch young. In fact, 17 of 25 females captured during the Pilliga’s December survey were carrying pouch young.  

The AWC says that detections of young animals are a significant measure of the Bilby’s ability to survive into adulthood within the safe havens. The process of breeding also means new recruitment of individuals for the protected populations which will contribute to larger population estimates in the near future. 

Reintroduced

Since the Greater Bilby was reintroduced to the Pilliga State Conservation Area in 2018, the population has undergone boom and bust in line with weather conditions. 

Last year, despite the turmoil of two flood events, Bilbies maintained good numbers with a population estimate of 175 individuals and signs of successful reproductive recruitment. 

Bilbies were reintroduced to the Pilliga almost a century after disappearing from the north-west NSW landscape. AWC with NSW National Parks and Wildlife Service (NPWS) released 60 individuals into a 680-hectare feral predator-free breeding area, where they have stayed until the final predator was recently declared removed from the wider 5,800 ha fenced area. 

Dr Vicki Stokes, AWC Senior Wildlife Ecologist, said survey results indicate that the population is doing well, and they are likely to thrive in the wider fenced area. 

“The Pilliga experienced two extreme weather events in October and November last year which we believe contributed to a discrepancy between survey results and population estimates in July and December 2022,” explained Dr Stokes. 

“High rainfall and flash flooding of creeks and forest areas may have resulted in mortality of some Bilbies, particularly if burrows were impacted by the floods. 

“However, the high proportion of females with pouch young encountered during the December survey, coupled with the healthy body weights and body condition of captured animals and sightings of numerous juveniles in February, suggest that the species continues to do well.”