Farmers across New South Wales and Queensland, as well as parts of Victoria and South Australia continue to battle mice plagues of once-in-a-lifetime proportions.
As many growers look to sowing winter crops, trying to get a handle on mice populations is an unwelcomed distraction.
On a University of Sydney research farm at Narrabri in New South Wales, Manager Guy Roth calculates a staggering figure.
“I know we had two mice per square meter in our cropping paddocks at the peak … [so] if I have the math right, it’s 20 million mice. That’s more mice than the population of most big cities,” he said.
Mr Roth said that he and his family were catching around 100 mice each day, just from their house and offices.
“They’re all around the house. Every time you open a drawer, you’re potentially going to find one,” he said. “You’ll be sitting at the desk and a mouse will run across it.”
According to CSIRO researcher Steve Henry, mice infestations are causing some farmers to abandon summer cropping programs altogether.
“Some farmers are giving up on summer crops … because the mice have damaged them so severely, so that’s essentially a total crop loss,” he said. “And in some scenarios where farmers have managed to get the crops through to harvest, they’ve had it rejected because it’s full of mouse poo.”
“We’ve had a run of dry years and [now] the drought has essentially broken, so the mice get switched on to that change in environmental conditions, and they start to breed. The farmers have had a good crop and that puts a lot of food into the system. So you’ve got favourable climatic conditions, favourable food in the system, lots of good shelter, lots of moisture.”
While the first cold days of winter will slow mice down, Mr Henry said that farmers shouldn’t rely on the weather alone.
“We hear about rainfall events ending outbreaks, big frosts ending outbreaks, but that probably doesn’t hold [true],” he said.
“Mice are digging quite extensive burrow networks out in paddocks and it’s pretty easy for them to get away from those nasty climatic conditions and continue to thrive if there’s plenty of food in the system.
“What will happen during the winter is that breeding will slow down … and mice go into self-preservation mode to get through winter so they’re still there in spring.”
Julian Cross from Kumbia in Queensland said that the mice problem has worsened since Easter.
“We’ve had a few in the past but never to this extent and it’s ongoing,” he said.
“They just bar into the cobs and chew on the corn and on the mung beans — they nibble at the pods and the pod dies.
“Like cockatoos, they only take a bite out of each one so 90 per cent of it gets wasted anyway.”
Earlier this week, the Government granted farmers permission to use a bait double the strength of normal poison.
In New South Wales, farmers have joined forces with the Country Womens’ Association to call for a $25,000 package to be provided to agricultural businesses fighting the plague.