Above average yields in parts of the southern cropping region are creating the potential for increased numbers of mice next season.
While mice have not been a major issue this year, populations can rapidly build if food sources such as spilled grain are plentiful over the months after harvest.
Supported by the Grains Research and Development Corporation (GRDC), pest management authorities are advising growers, particularly those in high-yielding regions, to take steps to discourage a potential build-up of mouse populations.
Biosecurity SA Research officer Greg Mutze says spilled grain in paddocks is the key that allows mouse numbers to build up rapidly and damage next year’s crops.
Mr Mutze said an elevation in mouse populations usually occurred the year after a bumper harvest.
“The problem arises when a lot of grain is left on the ground – a small percentage of a large harvest can equate to a significant amount of feed for mice. Some areas also had bad wind damage this year that dropped a lot of grain before harvest – that is the worst possible scenario if combined with summer rains which promote weeds and mouse habitat.
“And when plague situations occur, they tend to be in the more variable districts. They seem to be the areas more prone to damage and that is what we saw in 2010-11.
“Managing weeds over summer to reduce mouse habitat and food sources will be critical for areas with large grain losses, but even with the best management over summer it is likely that some baiting will be required at seeding next year.”
Other measures that can be taken over the coming months to curb mouse breeding include:
- For those who are still running sheep, heavy grazing immediately after harvest to help clean up harvest grain losses (ensure sufficient ground cover is left to minimise erosion potential).
- Cleaning up any concentrated spills of grain around field bins, augers, silo bags and other grain storage.
- Removing or reducing cover, including plant material, rubbish and general clutter around buildings, silos and fodder storage as these all provide protection for mice
Meanwhile, a new three-year GRDC-funded study to monitor and model mouse populations across the grain belt of Australia is well under way. The project is a collaborative project between Landcare Research (New Zealand), CSIRO Ecosystem Sciences and the Invasive Animals Cooperative Research Centre.
The aim of the project is to monitor mouse populations across grain growing areas and develop predictive models to forecast outbreaks. It will also disseminate the results of the monitoring and predictions to farmers and industry through the GRDC to improve awareness of and preparedness for increases in mouse activity.
Information and outcomes from the three-year monitoring project will also be relayed to the National Mouse Management Working Group (NMMWG) which was set up with GRDC support in 2011 to co-ordinate actions to counter mouse plagues and to facilitate bait availability on-ground when needed.
Mouse populations will be monitored in typical cropping systems in South Australia, Victoria, New South Wales, Western Australia and Queensland at three key times each year, coinciding with important crop stages and critical times in the build-up of mouse populations.
The monitoring will be used to collect information about the abundance of mouse populations, breeding status and overall activity.
This information will be fed into mouse prediction models that have been developed over the past 20-30 years. These models were developed at long-term monitoring sites at Roseworthy in SA, Walpeup in Victoria and the Central Darling Downs in Queensland.
Monitoring of mouse populations will occur at three levels of intensity across 11 sites.
Further information on mouse monitoring and management is available via the GRDC fact Sheet, www.grdc.com.au/GRDC-FS-MouseControl.
Caption: Reducing mouse habitat and food sources will be critical for areas with large grain losses.
Greg Mutze, Biosecurity SA
08 8303 9505
Sharon Watt, Porter Novelli
GRDC Project Code
South, North, West, National