Koalas and eastern bettongs reintroduced into the first feral predator-free national park in the heart of western Sydney are thriving and have now been joined by the New Holland mouse, which was once presumed extinct in NSW.
The first group of tiny native rodents was recently released into Yiraaldiya National Park and monitoring with micro transmitters has confirmed the population is adapting to its new home.
This is the first ever translocation of the New Holland mouse in NSW. The reintroduction of 18 pioneering mice is the first step to establishing a self-sustaining, wild, genetically diverse population in Yiraaldiya.
Native rodents contribute to the restoration of important ecological processes, such as seed dispersal, which have been missing due to the local extinction of all ground dwelling native animals from the area.
The New Holland mice join the 4 male eastern bettongs who have called Yiraaldiya home since June last year, and a a trio of koalas released in April and July 2023. Further translocations over the next few years will see the bettong population reach around 150 individuals, and additional koalas will be reintroduced and managed as part of the broader meta population in the region.
NSW National Parks and Wildlife Service (NPWS) monitoring shows a year after being introduced to their new home, all koalas and eastern bettongs have gained weight and body condition.
In the future NPWS plans to return up to 30 other locally extinct species to Yiraaldiya, making it one of the world's biggest urban wildlife restoration projects.
These species include the brown antechinus, long-nosed bandicoot, common dunnart and bush rat which are no longer found in the area.
The fenced feral predator-free area at Yiraaldiya provides protection from key threats such as predation from foxes and feral cats.
Yiraaldiya is one of a network of feral predator-free area projects underway across the state by NPWS. Once all sites are established, almost 65,000 ha of national park estate will be free of feral predators.
Australia has the worst mammal extinction record in the world, with the primary driver of extinction and decline being predation by feral cats and foxes.
NPWS has a zero-extinction target and is working to create permanent strongholds for the conservation and recovery of all threatened species.
The feral predator-free projects are jointly funded by the NSW Environmental Trust and NPWS.
The New Holland mouse project is being delivered in partnership with the Australian National University and the Woodlands and Wetlands Trust.
Quotes attributable to Atticus Fleming, Deputy Secretary, NPWS:
'Since European settlement, 11 native rodents have become extinct across Australia.
'The New Holland mouse was presumed extinct in NSW until it was rediscovered in Ku-ring-gai Chase National Park in 1967.
'Returning this species to its former home range is part of a broader strategy to turn back the tide of extinctions.
'Up to 100 New Holland mice will be released over the next two years and the population is expected to grow to over 2,500 individuals or more during good conditions.'
Yiraaldiya's new residents
Koalas
- Trio of koalas released in early 2023.
- The koalas wear solar-powered GPS tracking collars which allows 24/7 monitoring.
- All have gained weight and body condition and established home ranges in the park.
- The Yiraaldiya population will form an important source of genetically diverse, disease-free koalas suitable for an ongoing translocation program.
Eastern bettongs
- Small hopping marsupial related to kangaroos.
- Known as ecosystem engineers as their digging protects and restores ecosystems by promoting healthy soils and seed germination.
- The first release of four eastern bettongs occurred in June 2023. The next release is planned for 2025.
New Holland mouse
- Is a native Australian rodent that eats seeds, flowers, fruit and leaves.
- The New Holland mouse plays an important role in seed dispersal.
- First cohort of 18 mice were released in late May 2024.
- Each is microchipped and will be tracked after release using microchip readers at supplementary feed stations during the initial translocation to monitor their progress.
About Yiraaldiya
- Yiraaldiya National Park is in western Sydney.
- All species being considered for reintroduction once lived in this location on the Cumberland Plain.
- Establishing the feral predator-free area involves 2 stages:
- Stage 1, is the creation of a small soft release area of 56 ha within the national park.
- Stage 2, is the majority of the reserve, with the feral predator-free area encompassing 555 ha of the park.
