Farmers and communities across large swathes of inland eastern Australia are being hit by their worst mouse plague in almost a decade, threatening to undermine post-drought recovery efforts.
Mouse populations have spiked over the past 12 months as crop-growing conditions have improved across rural Australia and provided the rodents with favourable conditions for eating and breeding.
Elevated mouse populations have been recorded from Central Queensland down to northern and central west NSW and into western Victoria.
In some areas, problems with mice have reached plague-level proportions.
CSIRO mouse researcher Steve Henry told AAP mice feast on the stubble of crops and reproduce roughly every three weeks once they reach six weeks old, making population control a near-impossible task.
The last big mouse outbreak in Australia occurred around 2011.
“The mice have continued to breed through the spring, into the summer and now the real concern is that they’ll continue to breed into the autumn and cause a lot of trouble for the sowing of winter crops (in March/April),” Henry said.
“You can force a farmer to do something about rabbits or foxes but because they’re all-pervasive when in high numbers, everywhere you turn there’s a mouse … it’s just impossible to get on top of them.”
Such an outcome, according to Coonamble Chamber of Commerce president and newspaper proprietor Lee O’Connor, would be disastrous for rural communities only just emerging from years of drought.
The central west NSW town – situated in the state’s “wheat belt” and famous for Australia’s biggest rodeo and campdraft – has since November battled booming mouse numbers in both farm paddocks and homes.
In some places, the boom has caused a shortage of mouse baits and traps.
The Centre for Invasive Species Solutions’ “FeralScan” online reporting tool lists seven major mouse sightings in the past 12 months around Coonamble, with mouse populations “widespread and obvious in paddocks”.
“One supermarket said they were catching 200 a night, there have been people catching a couple hundred in their pool filters every night,” O’Connor told AAP.
“They’re in beds, people getting nibbled on at night … it’s everywhere.”
O’Connor, the wife of a cattle, sheep and grain farmer, admitted being concerned about the prospects for the 2021 winter crop if mouse numbers fail to decline.
The mice both destroy crops and eat feed intended for cattle and sheep.
“It’s obviously the topic that plays on (farmers’) minds, everyone’s hoping something will happen to stop it,” she said.
“It’s coming up to sowing time, and they’re all through the paddocks. There are already people who have sowed summer crops and have had to re-sow.”
Henry recommended farmers allow their sheep to graze at crop stubbles to reduce the mice’s food source, spraying germinating plants and baiting at least six weeks before sowing crops.
Should that fail, farmers should drop bait straight off the back of their seeders as they sow.
The NSW Department of Primary Industries said in a statement that regular monitoring was “the key to ensuring the frequency and severity of mouse plagues is kept as low as possible”.
The department does not typically intervene in mouse plagues as they are not deemed a noxious species.
But O’Connor said some government help – such as subsidies for mouse bait – would be greatly appreciated.
“It’s across quite a wide area of inland NSW now and it’s something they probably need a concerted effort for … in a way it’s no different to a locust plague, and the government agencies all get involved in that,” she said.
Angelo Risso in Sydney