New Species Introduced to Sydney’s Only Feral Predator-Free National Park

A group of 18 New Holland mice have been reintroduced to Yiraaldiya National Park in Western Sydney, the first feral predator-free national park in the Greater Sydney area. The new residence are thriving alongside other marsupials in the park, including koalas and Eastern bettongs.

The New Holland mouse was once thought to be extinct in NSW, but in May this year, 18 were released into Yiraaldiya National Park‘s predator-free area. The goal is to establish a self-sustaining, wild, genetically diverse population in the park. NSW National Parks and Wildlife Service (NPWS) uses micro transmitters to monitor the native rodents and so far reports show the mice are settling into their new home nicely.

Atticus Fleming, Deputy Secretary, NPWS says, ‘Returning this species to its former home range is part of a broader strategy to turn back the tide of extinctions’.

Ground-dwelling native animals like the New Holland mouse contribute to important ecological processes such as seed dispersal.

The New Holland mouse has been released into the Yiraaldiya predator-free area in the hopes it will thrive

Last year a trio of koalas and four Eastern bettongs were also released into Yiraaldilya National Park. Monitoring over the past year shows they’re all happily living their best lives with weight gain and good body condition.

A koala post-release with its monitoring gear | Photo by Peter Taseski DPE

There’ll be further translocations over the next few years, hoping to see the bettong population reach around 150 individuals. More koalas will also be reintroduced into the area as well as 100 more mice.

The Eastern bettong is one of three species reintroduced into the Yiraaldiya National Park |Photo by NPWS

What is a predator-free area?

NPWS has created a predator-free area within Yiraaldiya National Park. The fenced area protects vulnerable land-dwelling native animals from foxes and feral cats which contribute to Australia having the worst mammal extinction record in the world.

‘Since European settlement, 11 native rodents have become extinct across Australia’, Fleming says.

Yiraaldiya is just one of eight current feral predator-free area projects underway across NSW. Once all eight sites are established, almost 65,000 hectares of national park estate will be free of feral predators.

Yiraaldiya Feral Predator Free Area | Photo by Zain Kruyer

Yiraaldiya National Park’s Newest Residents

The reintroduced koalas wear solar-powered GPS tracking collars for monitoring and form an important source of genetically diverse, disease-free koalas suitable for an ongoing translocation program.

One of the reintroduced koalas during a health check | Photo by Johny Spencer

The Eastern bettong is a small hopping marsupial related to the kangaroo. Its digging promotes healthy soils and seed germination, protecting and restoring ecosystems. The next release of Eastern bettong into Yiraaldiya is planned for 2025.

An Eastern bettong has its first look at its new home in Yiraaldiya National Park | Photo by P. Taseski NPWS

The New Holland mouse was thought to be extinct in NSW until it was rediscovered in 1967. This little rodent eats seeds, flowers, fruit, and leaves, playing an important role in seed dispersal. The new residents at Yiraaldiya are microchipped and have been monitored during translocation at supplementary feeding stations.

Feature image by Zain Kruyer