GRDC mouse surveillance and modelling

Full description

The purpose of these projects is to predict house mouse abundance across grain growing regions to provide early warning of potential mouse plagues.
This data has been collected by CSIRO and subcontractors; CSIRO has collated and cleaned this data into this joint dataset.
House mice are surveyed in crops using three different methods: live-traps, active burrow counts and chew cards.
Live trapping currently only occurs at three properties (two paddocks are monitored simultaneously). Active burrow counts and chew cards (i.e., rapid assessment) surveys are also conducted in each paddock simultaneously over one night.
In all other sites, only rapid assessment surveys are conducted. In some instances, active burrow counts are not conducted as visibility of the burrows is too low due to dense crops or because of prolific soil cracks.
In these cases, chew cards are still deployed, sometimes with higher effort.
Each data type is provided as a separate CSV file, which contains a series of common variables denoting sites and times, as well as dataset-specific columns describing effort and results.

Lineage: Trapping description:
Live-capture trapping data using Longworth, Elliott, or snapback traps.
Data is aggregated at individual survey nights, except for sex ratios and breeding indicators which is summarised over the 3-night trapping session at the site (farm).
Generally, at a site (farm), two subsites (adjacent paddocks within the farm) are surveyed over 3 nights.
36-traps are deployed in a grid formation with 10 metre spacing within each subsite
Traps are baited with wheat, checked daily, and animals are marked with ear punches for capture-mark-recapture analysis (no individual identification however).
Active burrow counts and chew cards are also surveyed at each subsite, approximately 100 metres away (these are linked with the same site, subsite variables.

Burrows description:
Rapid assessment data type based on active burrow counts along fixed transects.
This provides a quick index of mouse activity without requiring live capture.
Burrows are searched in 100 metre transects, generally 4 transects at a subsite are searched with 10 metre spacing.
Counts of active burrows are recorded in four 25m segments for each transect in the raw data sheet (here derived to counts in each transect).
Transects are searched twice: first to cover any identified potential burrows with flour, second the next day to look for signs of mouse activity (fresh digging, tracks, etc.) at each burrow to determine whether it was active the previous night.
Only burrows with signs of activity are recorded.
Active burrow searches are not conducted when detectability is considered too low due to ground cover obscuring the view. In this case the site is still monitored using chew cards.

Chew card description:
Rapid assessment data based on chew card activity. Chew cards are paper cards
soaked in vegetable oil and pegged to the ground. Rodents chew the cards,
providing an index of activity. The percentage of each card eaten is recorded.

Oil-soaked paper cards (10×10cm with 1cm grid) are pegged to ground, typically
in lines or grids with 10m spacing. Cards are checked the next day and
the percentage eaten is estimated using the grid pattern.