Stick-nest building mammal back in the Mallee

It builds its home out of sticks and stones, lives in extended family groups, and went extinct in New South Wales over 160 years ago – but now the Greater Stick-nest Rat is back!

Last month, Australian Wildlife Conservancy (AWC) returned 40 Greater Stick-nest Rats (GSNR) to mainland Australia’s largest (9,570 hectares) feral predator-free area at Mallee Cliffs National Park, in partnership with the NSW National Park and Wildlife Service as part of the New South Wales Government’s Saving Our Species program.

With the temperament and size of a guinea pig, these small native rodents were transported in their family groups from Monarto Zoo in South Australia to Mallee Cliffs, where they were released into smaller pens. After a short period of observation, they will be released into the wider area, where a thriving population Greater Bilbies have already been reintroduced.

AWC Chief Science Officer, Dr John Kanowski, says the Greater Stick-nest Rat used to occur from western NSW to Western Australia. Wiped out by feral cats, foxes, rabbits and loss of habitat on mainland Australia, it has clung precariously to survival on the Franklin Islands, in the Great Australian Bight.

“Translocations to feral cat- and fox-free havens have helped save this species,” Dr Kanowski said.

AWC has already successfully established a population of Greater Stick-nest Rats at its Mt Gibson Wildlife Sanctuary in Western Australia. There are other reintroduced populations on some islands in South Australia and Western Australia, and at the fenced Arid Recovery reserve.

“AWC is using knowledge gained from the successful reintroduction to Mt Gibson to guide this work.”

“Projects like this are great for conservation – a win for the species and another step in restoring the environment at Mallee Cliffs National Park.”

The last record of the GSNR in the wild in NSW was made by naturalist Gerard Krefft in 1857, when he camped for nine months on the Murray River, near present-day Mildura. Helped by local Aboriginal people, he described an unusual rodent (called “Kohl” by the local people) that built its “huts” out of sticks.

While small in stature, they are prodigious builders. Major Mitchell, the explorer, described its “enormous nest of branches and boughs,” built like an old-fashioned beehive. Gathering material in their mouths, they build nests up to a metre high and 1.5 metres wide. The nests are a feat of engineering, with extensive tunnels and chambers where the rats place grass and soft vegetation.

The aptly-named stick-nest rat lives in intergenerational family groups. They feed on the leaves and fruits of a variety of plants, preferring succulent and semi-succulent vegetation.

With a body length of 17 to 26 centimetres, they weigh up to 450 grams, have fluffy yellow-brown to grey fur on their upper body and cream fur below, a blunt snout, large, dark eyes and large, rounded ears. They also have a long tail and distinctive white markings on its feet.

Breeding can occur year-round but usually peaks in autumn and winter. Females give birth to up to three well developed young which secure themselves to their mother’s teats for about a month before reaching independence.

The Greater Stick-nest Rats released at Mallee Cliffs were part of a breeding program at Monarto Zoo, in South Australia. AWC ecologists collected wild founders for the breeding program from the Franklin Islands in 2019.

Zoos South Australia’s Conservation Manager Dr Liberty Olds says the results have been fantastic.

“We’re thrilled to say the breeding program was incredibly successful and all the animals arriving at Mallee Cliffs today are offspring of that original wild population.

“They’ve grown brilliantly and have all been given a clean bill of health from our vets before being released.”

The Mallee Cliffs project is funded under the NSW Saving our Species program. NSW Environment Minister, Matt Kean, says it will turn the tide on extinctions by reintroducing threatened mammal species to the state.

“The greater stick-nest rat was one of just a few mammals that were thought extinct until their rediscovery on cat free havens off mainland Australia,” Minister Kean said.

“The journey for the Mallee Cliffs rats began on one of these offshore havens where individuals were selected to be part of a breeding program at Monarto Safari Park in South Australia. These are their offspring.”

“The reintroduction is part of a major NSW Government initiative which includes the establishment of Australia’s largest feral cat-free area at Mallee Cliffs,”

In its fifth Global Biodiversity Outlook report, released last month, the United Nations warned that biodiversity continues to decline at an “unprecedented rate”. AWC CEO Tim Allard says more needs to be done to stop this decline in Australia.

“Australia has the worst rate of mammal extinctions on the planet, and this loss of our precious natural capital is escalating. We now have over 50 mammal species at risk of extinction. Once gone, they are gone forever.

“This project with the New South Wales Government will make a significant positive impact on the global population of Greater Stick-nest Rats and will prevent it from experiencing the same tragic fate as its cousin, the extinct Lesser Stick-nest Rat.”

Media enquiries:
Heather Paterson, Communications Manager: 0476 829 523, heather.paterson@australianwildlife.org
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