While many rural residents are relieved the use of a poison described as “napalm for mice” has been rejected, communities remain desperate for a stronger tool to fight the mouse plague.
- The NSW government lodged an urgent application for the poison bromadiolone to be permitted for use in in-crop baiting
- It was knocked back by the independent authority this week due to concerns for safety and the environment
- There were concerns the poison would also have a major impact on wildlife including fish and birds as well as pets
In May, the NSW Government lodged an urgent application with the Australian Pesticides and Veterinary Medicines Authority (APVMA) to authorise the use of anti-coagulant poison bromadiolone in broadacre farming to try to eradicate mice.
This week the application was knocked back by the independent authority, citing concerns for safety and the environment, particularly for what bromadiolone’s high rate of secondary deaths would mean for other animals.
Narromine farmer Stu Crawford said despite the severity of the mouse plague, he wouldn’t have used the poison if it had been approved.
“I don’t think any farmer wants to see indirect consequences from a poison, I think there were too many risks from the product to follow through with it,” he said.
“We wouldn’t have used it if it was approved, we’ve been happy with the performance of zinc phosphide.”
What will spring hold
The Narromine mixed farmer says locals are prepared for the worst in spring.
“The sleeping giant is what mice will do in the spring [when breeding escalates]. That will very much depend on what happens to the populations in winter,” he said.
“We’re all very aware it could become a big problem.”
“There’s no easy fix for the plague, hopefully Mother Nature steps in soon.”
Residents at wits’ end
Coonabarabran resident Susanne Sovic isn’t as relieved by Bromadiolone’s rejection.
“While people clap and cheer about this poison being rejected, another farmer walks away from the land,” she said.
“More kids have to suffer because their school books and uniforms are eaten by mice, not to mention their poor parents struggling with mice through their houses, eating wiring in their cars, chewing electrical wires in their homes. The list goes on and on.
“Yes, there would be secondary poisoning effects on wildlife but people in their homes out here are already spreading poison,” she said.
“Come and take a drive at night [in a mouse plague-impacted area] and drive till the road is carpeted with mice. People wouldn’t be so happy about this decision if they were suffering from the plague.”
Winter won’t end the plague
There are real concerns about the mouse plague worsening in spring when conditions warm up and breeding escalates.
“Breeding generally stops through the winter every year so we would be expecting mouse numbers to plateau over the next couple of months,” CSIRO mouse expert Steve Henry said.
“We’re still sure there are lots of mice in the system.
“This month in Parkes we trapped over 3,000 mice in a two-week period. We need to be really vigilant about how many mice make it through the winter time for when breeding starts again in spring.”
Unfortunately the cold, wet conditions during winter are not expected to end the mouse plague, with mice hiding in burrows to escape the harsh conditions.
Residents must be vigilant with mouse baiting and it’s hoped approval to double the potency of the poison currently being used will have a big impact.
“The double dose zinc phosphide should be quite successful, we haven’t tested it in the field yet but we should have some of those results soon,” Mr Henry said.
‘No silver bullet’
Dubbo environmentalist Mel Gray said while the plague was a devastating problem, she believed bromadiolone was a terrible option.
“A lot of native animals have been feasting on mice, including threatened species of Murray cod which people found surprising,” the Healthy Rivers Dubbo convenor said.
“They’re voracious predators.
“Goannas, raptors, owls, wedgetail eagles and fish are all gorging themselves on these mice,” she said.
“Bromadiolone is a particularly insidious type of secondary poison. We can’t just expect to be able to treat one part of the ecosystem – an out-of-control mouse plague — and not have serious knock on impacts with other species and the human food chain as well.”
Ms Gray said there was no safe, quick fix to the mouse problem.
“The mouse plague is a horrible thing. There’s no silver bullet,” she said.
“I understand the government really wanted to come out … with a strong way to deal with this mouse plague, but there’s nothing like that.
“I think this mouse plague has to be dealt with over time with a series of different solutions [such as] land management solutions [and] continuing with the poisons we’re using now that aren’t so dangerous for the environment.
“It’s a relief that APVMA saw fit to step in and common sense prevailed.”