Mouse Ecology Project: Research Activities
Through a series of field trials we’ve been investigating the effect of specific crop management practices on mouse activity, behaviour and populations at different times of the year and grain growing season.
Damage at sowing
Mouse damage at sowing is difficult to quantify. We undertook a pilot trial to see whether we could measure mouse damage at sowing by assessing germination rates within mouse-proof exclosure cages. We also compared mouse damage at germination between crops sowed with ‘knives’ and ‘disks’.
Left: A team member counts seedlings protected by a mouse exclosure cage. Right: Cages were set up immediately after sowing and revisited a few weeks later to compare germination rates within cages (mice excluded) to those adjacent to cages (mice accessible). Images: Wendy Ruscoe
Bait spreading
By examining mouse habitat use within paddocks we’re investigating whether baiting efficiency can be improved. Currently zinc phosphide (ZnP) mouse bait is spread at a rate of 1 kg/ha from spreaders on the back of farm machinery to achieve a uniform application within crops. If mouse habitat use is concentrated around certain resources in paddocks (like burrows, food or cover) then bait spreading may be able to be targeted around these areas.
Chaff-lines
Do chaff-lines affect the distribution and availability of food resources and cover for mice? We investigated this by comparing conventional harvesting (chaff spreading) with chaff-lining by monitoring mouse population dynamics throughout harvest (mouse survival, population abundance, breeding, movements).
During harvest the header leaves lines of chaff behind (left). Chaff contains weed seeds and chaff-lining is used as a weed management tool, however chaff-lines may also provide mice with concentrated food as well as cover from predators like raptors (right). Images: Peter Brown & Nikki Van de Weyer
Food availability over the growing season
We’ve been investigating the role different crop management practices have on mouse foraging and diets by examining the spatial distribution of food supply and cover within paddocks before harvest, at harvest and after harvest.
Stubble management
Standing stubble can act as cover for mice from predators, so removing that cover may alter mouse behaviour (and ultimately survival) as the risk of foraging and moving out in the open is greater. We investigated whether various techniques of flattening or rolling standing stubble after harvest could reduce mouse abundance in paddocks.
Left: a stubble being rolled. Newly flattened stubble is visible in the foreground. Right: live-capture trapping in a rolled stubble. Capture-mark-recapture of mice before and after rolling stubbles can indicate whether mouse abundance has changed as a result. Images: Steve Henry & Freya Robinson
Sheep as a tool to reduce mouse food
Farmers put sheep onto their paddocks follower harvest to fatten on the residual stubble and spilled grain. This practice may reduce the food left in the paddocks, which may become available to mice. We identified four paddocks, two with sheep and two without sheep. We live trap animals, collect spilled grain samples, and count burrows on the grids.
Paddock without sheep. Image: Nikki Van de Weyer
Paddock with sheep. Image: Nikki Van de Weyer
How are we collecting all this information? Our Research Techniques page outlines the many field research methods we’re using.