Mouse plague threatening Western Australia’s billion-dollar grain crop as numbers explode

Rat plague could threaten the $1 billion grain crop in Western Australia if urgent action is not taken, scientists have warned.

Farmers have found about 4000 nests per hectare in crops in the Mid-West, Wheatbelt and Goldfields-Esperance regions in Western Australia.

CSIRO research officer Steve Henry said there were large numbers of mice roaming wild in Western Australia’s cropland, with up to 8000 mice per hectare seen in some grasslands.

“This is a really serious situation,” he told radio station 6PR.

Mr Henry said farmers were becoming aware that mice were everywhere as they prepared to plant crops and needed to take action before the mice ate the newly planted seeds.

“They move through the planting rows and dig out and eat every seed planted,” he said.

“It’s a significant impact on yield, especially in crops like canola; when plants are destroyed it’s a significant loss for the farmer.”

WA Farmers CEO Trevor Whittington said it was one of the worst outbreaks, threatening $1 billion worth of grain production.

Mr Whittington said the plague affected grain crops, including wheat, barley, canola and other crops.

“The situation is about to get a lot worse because of the cyclonic rain they just received,” he said.

“It’s still hot, the numbers are already incredibly high, and they’re going to explode again.

“Farmers have just started feeding, their first germination will be in a few days and there will be nothing else to eat.

“That’s a big concern.”

Farmers couldn’t access a high-strength feed called ZP-50 without approval from federal authorities, Mr. Whittington said.

Along with other issues arising from the fuel crisis, fertilizer shortages and low grain prices, Mr Whittington said this was another complex issue affecting farmers in Western Australia.

Farmers need a federal exemption to access mouse bait, he said, but they have to wait for a decision.

“It came at the worst possible time, another problem that growers didn’t need,” he said.

Farmer Belinda Eastough said after years of good harvests and larger crops, more grain was left behind, providing more shelter and food for the mice.

He said that the conditions were suitable for the mice and that they had been breeding since spring and reached very large numbers.

Ms Eastough said baiting was the only option available to growers and it was the property owner’s responsibility to resolve the issue.

“If they have the bait on hand and can spread the bait, they can usually minimize the impact,” he said.

“However, if there is too much other food in the system, the feed currently offered to them becomes less effective,” he said.

“To get a lethal dose, it’s a matter of mice finding two or three grains of the toxin, and if there’s too much other food in the system, their chances of finding those grains decrease.”

Ms Eastough said the last time they had a rat plague, farmers in the area were catching about 40 rats a day in their homes.

“It would be great to see another emergency payment, we need them,” he said.