AUTHORITIES are warning that in spite of cold and rainy weather across Victoria and South Australia, areas impacted by the mouse plague earlier in the year will again be under severe pressure from the rodents come spring.
Steve Henry, a CSIRO researcher looking into mouse numbers with funding from the Grains Research and Development Corporation (GRDC) said while mice generally did not breed over winter, several reports had come in of abnormally high mouse loads for this time of year.
“We’ve got reports of farmers actively spreading bait already, which is very early, they had been noticing tiller damage.”
He said the problems were worst in the areas that had high mouse numbers in autumn, such as South Australia’s lower Mid North and Yorke Peninsula and the Wimmera in Victoria.
“There’s no doubt people are concerned, Agriculture Victoria held an event regarding managing mouse numbers, expecting 30-40 farmers across three days, instead there were 200,” Mr Henry said.
He said the key piece of advice for growers was to get out and closely investigate paddocks.
“With the crops growing it is not really possible to pick everything up from the ute cabin,” he said.
“You need to get out and have a walk between the rows to really get a feel for what is happening.”
Mr Henry said he felt baiting would be necessary for many growers again.
“It is quite concerning the early reports that appear to show a reasonable population of mice has survived, and with a good season for crops it is very likely they will begin to breed up again.
“If we start with a higher than average base with better seasonal conditions you could see numbers climb rapidly.”
He said each female mouse was capable of producing up to 500 offspring a season, meaning numbers multiplied to problem proportions very quickly.
Kalkee, north of Horsham, farmer Steve Schultz said mouse numbers were noticeable but not yet at problem levels on his Wimmera Plains property in Victoria.
“You can find them if you look hard enough for them, but in general they are not yet as big a problem as they were in the autumn.”
He said he had been forced to replant barley at sowing time due to mouse damage and was watching carefully to see if numbers rebounded following winter dormancy but as yet it has not happened.
“We’re looking for that second wave, but we are yet to see them come out in big numbers.”
Garry Hansen, Coomandook, South Australia, said the Upper South East had not been the major focus of mouse problems in SA.
“We did have issues with mice, and most guys baited, but it was probably not as significant as places such as Mallala (in the low Mid North).”
He said some growers had already baited twice for mouse control, particularly in canola crops on barley stubble.
“There was a lot of food on the ground, particularly for guys who did not have sheep eating the feed up.”
“It will be something we keep a close eye on through spring.”
The 2017 mouse plague has been most significant in SA and Victoria, with some smallscale issues reported in NSW’s Riverina.