Region’s eyes turn to mice
Authorities continually assessing information about mouse numbers across north-west Victoria say it is too early to predict if the pests will reach plague proportions this year.
Agriculture Victoria natural disasters and emergencies manager Banjo Patterson said conflicting reports on a build-up of rodent numbers were painting an inconclusive picture.
He said while conditions were in many ways conducive to a widespread mouse-population increase, December surveys had shown numbers to be low.
“But we’re getting mixed messages and we have some people saying they have seen a significant build-up,” he said.
“What that tells us is that it is too early to predict what might happen and we simply have to wait and see.
“It all works on irregular patterns and while we’ve had quite heavy crops and there is more grain on the ground than usual, there are also factors such as rain and summer-weed seeds to consider.”
The CSIRO warned in January that Victorians and South Australians should expect a build-up in mouse numbers as a result of last year’s wet spring.
Ecologist Steven Henry said at the time that climate, food and breeding were the three key factors that could contribute to a plague.
He said the breeding season usually started in late August or September, but researchers had found it had started in early August.
He added readily available food meant mice could concentrate more on breeding instead of using energy for foraging and that could continue unless hindered by hot, dry weather.
“This means there is potential for ‘greater base population’ ready to procreate when farmers starting sowing in autumn,” Mr Henry said.
The region has had some extreme hot days but many people monitoring environmental conditions believe the summer season has been relatively mild.
Mr Patterson said Agriculture Victoria used information from the CSIRO as well as other sources to monitor mouse numbers across the state.
“We also talk to individual growers and groups such as Birchip Cropping Group, so it is a mix,” he said.
“What we suggest is growers record and map activity on the web with the Mousealert website and mobile phone app.
“The next big risk time will come in sowing in autumn and the potential damage to newly sown crops.”
Australia’s most financially devastating mouse plague came in 1993 when the rodents caused an estimated $96-million worth of damage in the cropping and livestock industries.
The pests not only eat crops, but attack animals and poultry, foul water storages and are driven by hunger to chew through electrical cables.