Did you know that Tasmania is home to 11 species of native small mammal?
One of these is the endangered native rodent, the New Holland Mouse (Pseudomys novaehollandiae). This incredibly rare species has been recorded from coastal heathlands and associated vegetation on the north-east of Tasmania, including Flinders Island. The last in-hand record for the New Holland Mouse in Tasmania was in 2004.
DPIPWE has recently partnered with the Commonwealth as part of the Australian Government’s Bushfire Recovery for Wildlife and Habitat to conduct a Conservation Assessment for the species. This includes a systematic and intense survey effort across the New Holland Mouse's former recorded range.
Adult New Holland Mice weigh on average 25 grams, about the same as an AA battery. Because they rarely if ever interact with humans, surveying them requires specialist equipment. As part of the Conservation Assessment, white flash remote cameras have been custom modified to a shorter focal distance. This results in sharply-focussed, colour images that maximise the chances of confidently identifying the New Holland Mouse from the superficially similar and co-occurring introduced house mouse.
Remote cameras have been set at over 200 sites in New Holland Mouse habitat in Tasmania. Unfortunately, the New Holland Mouse has not yet been detected at any of these sites on either remote cameras or other survey devices such as hair tubes or in predator scats.
But what has become clear is that the survey techniques used, particularly the modified white flash cameras, are effective for detecting small mammals. While the New Holland Mouse has not yet been detected other rarely observed small mammals have. These include the white-footed dunnart (Sminthopsis leucopus), a small carnivorous marsupial weighing on average 20 to 30 grams.
This white-footed dunnart was captured on camera as part of the New Holland Mouse conservation assessment survey.
Less than 15 records of the white-footed dunnart have been lodged in the Tasmanian Natural Values Atlas over the past 10 years, yet our recent searches for the New Holland Mouse have captured at least four photographs of the white-footed dunnart.
It is likely that remote cameras, particularly those that can capture high-quality images of small mammals, may be a more effective means to survey for the white-footed dunnart than traditional techniques such as live trapping.
Meanwhile the search for the elusive New Holland Mouse continues.
Little or Tasmanian pygmy possum
Delivery of the New Holland Mouse Conservation Assessment is a collaborative effort between the Department’s Threatened Species and Conservation Programs, and the Natural Values and Conservation Branch. The Parks and Wildlife Service has provided valuable logistical support and local knowledge for the project.