Reports of an increase in mouse activity across Western Australia’s grain growing region haven’t come as a surprise to industry experts, who were expecting high numbers this year after a bumper harvest and significant outbreak in 2021.

Evidence of mouse activity has been observed in Geraldton, Kwinana West and Esperance port zones. Steve Henry, leading mouse expert and researcher officer at Australia’s national science agency, CSIRO, says growers were anticipating increased activity after grain was left behind in paddocks after a huge harvest.

Mr Henry says it was crucial that mouse activity was monitored over the coming months to ensure numbers don’t increase significantly throughout summer and autumn and to ensure growers and suppliers are as prepared as possible for a potential outbreak.

“Monitoring is important because often there’s a lag between discovering a mouse problem and having the resources to manage it,” he says.

“Bait manufacturers and suppliers can use information from monitoring sites to ensure they have adequate bait supply to provide growers when needed.”

“Growers and advisers can also ensure they’re implementing baiting and other management strategies when necessary to help reduce the impact of erupting mouse populations.”

GRDC has invested in additional surveillance and extension activities to alert Western Australian growers and advisers of the presence of mouse outbreaks across the state throughout the 2022 season and extend information on effective management tactics.

GRDC Crop Protection Manager - West, Georgia Megirian says this investment was developed in reaction to feedback from GRDC’s National Grower Network forums, which showed better mouse management was a priority for Western Australian growers, who were heavily impacted by mouse damage last year.

This project, led by Farmanco Management Consultants, will complement the additional $7.5 million GRDC has invested into mouse outbreak research, development and extension (RD&E) with CSIRO, centred around better understanding mice in cropping systems, such as the impact of residual food in stubbles, increasing surveillance and improving strategic management options.

It will also directly align with the existing GRDC and CSIRO investment that supports two mouse monitoring networks in Geraldton, managed by Great Northern Rural Services, and in Ravensthorpe, managed by Ravensthorpe Agricultural Initiative Network, which provide rapid assessments three times a year.

“Adding more surveillance sites across the state will ensure a broader picture of mouse populations and provide growers and industry information on the potential risk of crop damage from mice at sowing,” Miss Megirian says.

"This is when mouse populations are normally at their peak and can cause significant economic damage.”

Mr Henry says in response to an increase in activity, growers should be looking at implementing an integrated management approach to minimise damage from a potential outbreak.

Some key strategies to consider before and after sowing include:

• Controlling weeds and volunteer crops along fencelines, crop margins and channel banks before seedset to minimise sources of food and shelter
• Monitor mice through the stubble to enable timely control efforts at sowing
• When mouse populations are high at sowing, baiting at sowing may be necessary. Bait as the crop is sown to give mice the best chance of discovering the bait
• Coordinate management strategies with neighbours to minimise the risk of mouse re-invasion.

Findings from GRDC’s new mouse surveillance project will be reported to WA growers prior to sowing.

More information: for resources on mouse management.