Monitoring mice in Australia – Nov 2014

Nov2014_mapSummary

  • Moderate mouse abundance in some small pockets of northwest Victoria – some  damage might occur in maturing crops. Breeding started in early spring and mouse abundance could continue to increase. Farmers need to monitor mouse activity before harvest and manage mice to  protect their crops.
  • Low mouse abundance in Western Australia, South Australia, Victoria, New South  Wales and Queensland – mice are not likely to cause much damage as crops mature,  but farmers should continue to monitor.

Background

This is an update on mouse populations across the grain-belt of Australia for September/October 2014. Mouse populations were monitored in typical grains farming systems in Western Australia, South Australia, Victoria, New South Wales and Queensland during early spring 2014 (September/October). The monitoring provides data on the size (abundance) of mouse populations, their breeding status and overall activity. This information is used in models that have been developed progressively over the last 20-30 years to predict mouse outbreaks. Monitoring was conducted on:

  • Benchmark sites: live trapping data collected for use in models in Adelaide Plains (SA), Walpeup (Vic) and the Darling Downs (Qld).
  • Quantitative rapid-assessment sites: using mouse chew cards and active mouse burrows in 11 sites.
  • Qualitative monitoring networks: using data from farmers and agronomists in 11 sites.

Nov2014_LocationMapThis is part of a 3-year study funded by the GRDC to monitor mouse populations and forecast the likelihood of mouse outbreaks. The  project is a collaboration between Landcare Research (NZ), CSIRO Agriculture Flagship and the Invasive Animals Cooperative Research Centre.
Map right: Approximate locations of mouse monitoring occurring in WA, SA, Vic, NSW and Qld. Click on image above for a larger map.

Current situation

In all locations, mouse abundance is relatively low except for higher than normal mouse abundance in northwestern Victoria (Mallee).  Breeding commenced in early spring, and mouse numbers will increase through spring, into summer and reach a peak in autumn.  Mice are unlikely to cause significant damage to maturing winter crops across southern Australia, although there could be pockets of damage in northwestern Victoria (Mallee).

  • Western Australia: mouse activity is very low. Geraldton (November): nil activity (6/6 sites); Ravensthorpe (November): nil activity reported, and the weather has reportedly been very wet.
  • Nov2014_VicSASouth Australia: Mouse numbers now low across most of SA. The high mouse abundance observed in
    March has declined to low levels in June and September. Chew card monitoring in Yorke Peninsula in October March has declined to low levels in June and September. Chew card monitoring in Yorke Peninsula in October confirmed that mouse activity has declined to low levels. Damage to maturing crops is unlikely. Graph right: Current mouse population abundance at benchmark sites in Victoria and SA compared to outbreaks in the past (click on graph for larger view).
  • Victoria: Mouse abundance is generally low but increasing. Mouse numbers are slightly higher than usual for this time of year, particularly in northwestern Victoria (Mallee). Low levels of damage could occur to maturing crops, with some damage likely at sowing in autumn 2015. Growers will need to be vigilant leading up to sowing.
  • Central & Southern NSW: Generally low activity (nil or very low  chew card activity), but some chew cards eaten along a weedy  roadside, and observations of the odd mouse around. Data for  Central NSW were collected as part of the Central West Farming  Systems “Rain Grain and Stubble” GRDC project.
  • Nov2014_QldQueensland & Northern NSW: Very few mice observed on the  Darling Downs and Central Queensland. Very dry on the Darling  Downs. Monitoring in northern NSW will occur in early  December 2014.  Graph right: Current mouse population abundance at the benchmark site in  Central Darling Downs (Qld) compared to average abundance. (click on  graph for larger view).

Predictions of a mouse outbreaks

Central Darling Downs (QLD): There is a low likelihood of an outbreak in autumn 2015 (The medium-term probability for low  density in May 2015 is 0.51). The Darling Downs model has achieved 78% success rate from these long-term predictions over the period  of 1989 to 2003.
Northwest Victoria: There is a low likelihood of an outbreak in autumn 2015 (probability of 0.12). The prediction for Northwest  Victoria is dependent on rainfall in December. If December rainfall is  low (eg 0 mm), then mouse abundance will remain low. If  December rainfall is average (25 mm) then mouse abundance will  increase to around 20% and could cause low levels of damage. If  December rainfall is high (eg 50 mm), then mouse abundance will increase to 30-40% and could cause some damage at sowing.

MouseAlertAppFuture activities

The next scheduled monitoring will be conducted in autumn (March 2015) on all sites. The Smartphone “app” (MouseAlert, www.mousealert.org.au) was launched  through various workshops with growers in SA, Vic and  NSW. We encourage you to report mouse abundance (presence or  absence!) on your farm from your smart phone, tablet or computer  and to check what other mouse activity is being reported locally and  elsewhere. We welcome any information at anytime.

Further information

For further information about the monitoring or models, or if you have observed mouse activity in your area, please contact the people below:

Dr Peter Brown
CSIRO Agriculture Flagship, Canberra
Peter.Brown@csiro.au
Simon Humphrys
Invasive Animals CRC, Adelaide
Simon.Humphrys@invasiveanimals.com
Dr Roger Pech
Landcare Research, New Zealand
PechR@LandcareResearch.co.nz

 

Documents

Mouse Monitoring Update #5 - November 2014   [890kb PDF]