21 Feb Rodents on the Run
If you are anywhere in eastern inland Australia at the moment, you may have seen an abundance of mice either in your home or on your farm.
Where have they come from, and why are we seeing so many?
Mouse plagues can occur in any of Australia’s grain growing regions when the conditions are right. For ideal mouse breeding conditions there needs to be good moisture (rainfall) and a plentiful food supply. As crop-growing conditions have improved across rural Australia, this has provided perfect conditions which ensures large numbers of offspring per litter and high survival rates of young mice.
Mice start breeding at 6 weeks of age and can have a litter of up to 10 every 21 days after that, meaning a pair of mice can have up to 500 offspring in a season. That’s some super fast breeding and a lot of furry little pests that are wreaking havoc for many farmers and rural communities.
Image: CSIRO ScienceImage 3790 (Wikimedia Commons)
Mice are a significant problem in Australia, causing severe economic, social and environmental damage during plagues. Grain growing areas suffer damage to crops and to stored grain; rural businesses suffer damage from mice chewing stock and electrical wires; rural communities experience high levels of stress through the constant presence of mice. The also carry disease and therefore pose serious health risks.
How did mice end up in Australia?
The house mouse “Mus musculus” is one of the most widespread invasive species worldwide and in Australia, they are particularly common. Through DNA research, it has been determined that there is a very strong link between mouse populations in Australia and the British Isles so it is most likely that the first mice to arrive in Australia came from the British First Fleet in 1788. The earliest Australian specimen registered at a museum was collected in Tasmania in 1884.
What can we do about it?
For homes and buildings, it’s a matter of closing any gaps and holes so they can’t get inside, not leaving any food or crumbs around, ensure all food is stored in plastic or metal containers and generally using traps or baits. Farmers generally rely on mass-baiting programs such as the use of broad-scale zinc phosphide to get mouse populations under control.
Around the home, there are a few home remedies that may help – get a cat; sprinkle instant mashed potatoes around areas where mice are seen – they will eat the mashed potatoes which will expand in their stomachs and kill them; spray apple cider vinegar mixed with water around your home monthly; or place peppermint oil saturated cotton balls around areas of your home where you think mice are getting in – they don’t like the odour and will go to great lengths to avoid it.
As a reporting tool, and launched in 2014, the MouseAlert website and mobile app enable farmers and everyday residents to report mouse sightings. The tool is aimed at improving early warnings of possible plagues and provide rapid response to increases in mouse activity.
MouseAlert is a free resource that can be used by anyone to record observations of mice. Information you record can be used to manage mice more effectively to reduce the damage they cause and plan for control activities.
Image: Isaac Clarey – iNaturalist Australia