By Dr Greg Holland, Acting Regional Ecologist NSW
In 2016, Australian Wildlife Conservancy, in partnership with the NSW National Parks and Wildlife Service (NPWS) as part of its Saving our Species program, embarked on a historic project. AWC delivers ecological and land management services for two areas of the public estate: Mallee Cliffs National Park and the Pilliga State Conservation Area. Under this historic partnership, AWC is establishing large-scale, feral predator-free fenced areas and restoring regionally-extinct mammals at each park.
Following fence construction, an immense, sustained eradication program continues to be implemented at both Mallee Cliffs and Pilliga to remove feral animals within the fenced areas. These two areas form the largest fenced, feral predator-free refuges in national parks on mainland Australia. When completing projects on this scale, adaptability and perseverance are critical, with AWC employing a variety of techniques to achieve success.
Feral animal control – Mallee Cliffs
Construction of the Mallee Cliffs fence – protecting 9,570 hectares – was completed in August 2019. Efforts to remove feral animals include:
At Mallee Cliffs, eradication efforts have resulted in the removal of two cats, 12 foxes and 18 goats. Monitoring indicates feral cats have been eradicated inside the Mallee Cliffs conservation fence. With the recent removal of a fox, it’s hoped this species has also been successfully eradicated. Ongoing monitoring will verify this in coming months. Once confirmed, Mallee Cliffs will become the largest feral predator-free area on mainland Australia, wresting the title from AWC’s Newhaven Wildlife Sanctuary (9,450 hectares).
Feral animal control – Pilliga
The Pilliga fence, surrounding 5,800 hectares, was completed in July 2018. Eradication efforts included:
Specialist detection dogs have been used in the Pilliga to locate elusive feral predators. Four foxes, four cats and 59 goats have been removed. Feral cats have been successfully eradicated. One remaining fox is the subject of ongoing eradication efforts.
Reintroductions of threatened mammals
At Mallee Cliffs and Pilliga, a smaller ‘breeding area’ has been established inside the main fence. Population founders of each target species are sourced from genetically different populations. This area facilitates interbreeding to maintain and expand genetic diversity. Reintroductions commenced once feral animals were eradicated within these breeding areas.
Greater Bilbies were reintroduced to the Mallee Cliffs breeding area (480 hectares) in October 2019. The results are promising: survival in the months following reintroduction was ~90 per cent and individuals captured three months post-release were in good condition.
Two species have been reintroduced to the Pilliga breeding area (680 hectares): Greater Bilby in December 2018 and Bridled Nailtail Wallaby in September 2019. Survival in the months immediately following reintroduction was high (Bilby – up to 91 per cent; Bridled Nailtail Wallaby – 88 per cent). Individuals captured during routine post-release monitoring are healthy, with evidence of successful reproduction observed for both species.
Reintroductions – what’s next?
With each large fenced area soon to be declared feral- free, the partnership between AWC and NSW NPWS is entering an exciting new phase. Over the next few years, reintroductions of nine mammal species, including eight classified as Threatened, are planned for Mallee Cliffs, including Brush-tailed Bettong, Western Quoll, Greater Stick-nest Rat, Numbat, Mitchell’s Hopping-mouse, Bridled Nailtail Wallaby, Western Barred Bandicoot and Red-tailed Phascogale. Four reintroductions are planned for Pilliga, including Brush-tailed Bettong, Western Quoll, Western Barred Bandicoot and Plains Mouse. These reintroductions will help secure the long-term future of these species and restore important natural ecological processes at each site.
These reintroductions represent the most ambitious native mammal restoration program ever ventured in NSW. Under this historic partnership, AWC will ultimately restore up to 10 regionally-extinct mammals to NSW. Few projects have made such a significant contribution to the conservation of Australia’s threatened wildlife.