Rapid mouse response needed

Farmers need to take urgent action and wage war on mice where there are increased infestations.

As reported in _Countryman _ last week, data entered into the interactive MouseAlert website showed mouse activity was on the rise in some pockets of WA's south-eastern and northern grain growing areas.

Last year a plague - defined as more than 1000 mice per hectare - was reported independently in parts of the Esperance region, causing crop damage and economic losses.

The rise in the mouse population is probably due to ideal breeding conditions, boosted by a good harvest and followed by significant summer rainfall.

According to CSIRO researcher Steve Henry, this meant that there was higher than normal survival rates for mice through the autumn and winter.

"Then in the following spring, mice start to breed from a higher base and replicate quickly," he said.

A mouse starts to breed when six weeks old and a pair of mice can produce 500 offspring in one breeding season, Mr Henry said.

"Mice can cause trouble throughout the cropping season, but if there is an abundance during autumn they can follow the seeder along and eat the grain straight out of the furrows, resulting in no germination," he said.

Mr Henry said a possible reason for the longer-term increase in mice in WA could be the uptake of no-till and zero-till cropping systems, which provided favourable conditions for mouse survival.

He said growers who noticed significant increases in mouse activity on their farms should act quickly to manage the problem.

4Farmers general manager Neil Mortimore said in the past farmers commonly used Mouseoff sterilised grain as bait, which costs about $7 to $8 per kilogram and up to $10/kg in recent years.

However, 4Farmers about four years ago successfully registered an unsterilised zinc phosphide that is mixed with the farmer's own wheat to provide a similar mouse bait.

The cost, at about $2-$3/ha, is about a third of Mouseoff.

Applications rates are the same at 1kg/ha, and with both types of bait several applications may be necessary.

MouseAlert is available from mousealert.org.au or download the FeralScan app, which is available in the iTunes store.