Climate change has probably killed off an important native mouse in its Otways “home range”, according to a researcher.
The New Holland mouse was last recorded in the Otways and Anglesea Heath in 2003, but monitoring over the past four years failed to find any, said Deakin University Associate Professor Barbara Wilson.
“This leads us to believe that the New Holland mouse is most probably extinct from this habitat, something we did not expect to find,” the Deakin University ecologist said.
Reductions in rain from climate change were a “big threat” to the mouse, she believed.
“In the Otways, we had eight populations we studied. They were small and localised, but some were high density populations, especially after high rainfall.
“Unfortunately, when rainfall declined, the species declined.”
“Potential threats” to the species included land clearing, “inappropriate” fire controls, introduced predators and human impacts such as horse-riding and off-leash dogs),” Assoc Prof Wilson said.
She called for a range of actions to restore the mouse to the Otways, with other New Holland populations still surviving at Wilson’s Promontory, Dutson Downs and Providence Ponds.
“It’s now likely that the only way we will see a return of this species to the Otways is through a reintroduction program, but that must be supported by habitat protection, predator control and appropriate fire management if it is going to be effective,” Assoc Prof Wilson said.
She considered protection of the mouse critical, with the species having “historical and environmental significance“.
“Of Australia’s 49 conilurine rodent species – the group to which the New Holland mouse belongs – eight are extinct and 35 are in decline.
“Unfortunately, there’s not much monitoring of this kind of species, the money and public concern mostly flows to the bigger iconic mammals like koalas and numbats.
“A lot of the public don’t know we have native rodents, so we want to open up people’s minds to the small but significant species we have.
“There needs to be more resources put into regular monitoring of any wildlife listed as threatened.”
Assoc Prof Wilson said the New Holland variety looked “very similar” but was unrelated to the common house mouse”, which European settlers introduced to Australia.
The native species had slightly larger ears and eyes while lacking a distinctive “mousey” odour, she said.
The New Holland lives in coastal woodland and sand dunes. Small populations have previously been recorded in Tasmania, Victoria, New South Wales and Queensland.
Assoc Prof Wilson said small populations remained in Victoria, but many others were now extinct, including in Tasmania.