A CSIRO researcher warns that South Australia and Victoria could potentially encounter mice in plague proportions this autumn.
Steve Henry said he had surveyed mouse numbers in regions such as the Wimmera, Mallee and Adelaide Plains in late spring and had found mice had started breeding earlier than usual in these areas.
A good harvest, with plenty of grain spilt to the ground, now means there is abundant food for the vermin to feed upon as well.
Further increasing the likelihood of a mouse plague, Mr Henry said a relatively mild summer would allow numbers to build.
“A harsh, hot summer will limit breeding, but this season we have generally experienced fairly mild conditions.”
However, Mr Henry said while all the factors at present were combining to suggest potential issues with mouse numbers it was not a fait accompli and added there had been few reports of high mouse numbers as yet.
“At present it looks likely we could see mice in plague proportions in some areas, but a lot depends on what happens from now on.”
“What we are saying to growers is to keep a track of mouse numbers and activity.”
He said while rain would germinate grain on the ground, it did not mean the food source would disappear.
“Mice can eat the green shoot, so farmers will need to control summer weeds and volunteers if they want to limit the food source for the mice.”
Mr Henry’s work is part of a Grains Research and Development Corporation (GRDC) funded project, said at present he felt north-west Victoria was the most likely place to see a mouse plague this year.
On the flip side, he said reports from areas that had problems with mice in 2016, such as northern NSW and the Darling Downs, were that mouse numbers were currently low.
According to the GRDC’s Mouse Control Fact Sheet, mouse plagues usually follow a year of high grain production, particularly with heavy early or late-season rain.
Mr Henry encourages growers and advisers to report and map mouse presence, absence and level of activity using MouseAlert (www.mousealert.org.au) so others can see the scale and extent of localised mouse activity.
MouseAlert also provides access to fact sheets about mouse control and forecasts of the likelihood for future high levels of mouse activity in each grain-growing region.
“We need more producers using MouseAlert so that the project can deliver more accurate forecasts of regional changes in mouse numbers,” Mr Henry said.