Trapping Trapping for Feral Cats and Red Foxes occurred over two periods, 8 February – 4 March and 4–15 April 2011. Trapping for Cats was undertaken using treadle- operated cage traps (P&L Wire, Frankston) baited with fried chicken pieces suspended from the rear of the trap. These traps were in good condition and were known to be a successful design (Johnston, unpublished data). Cage traps (n=25) were set by experienced trappers in locations where Feral Cats had been trapped in previous years such as fence lines, stockyards, on the periphery of grassy clearings and near rabbit warrens. Trapping for Red Foxes was undertaken using rubber- padded leghold traps (Duke #1.5, West Point, USA). These traps were modified prior to use with a stronger base plate, additional swivels and were waxed and dyed by Outfoxed Pest Control. Leghold traps were set at 500 m intervals along every vehicle-accessible track within the study area (Figure 5). Trap sets used in the first trapping period were predominantly ‘dirt hole’ sets that utilised a single trap in a single entrance cubby. A variety of olfactory and food lures were utilised at trap sets including Cat-astrophic (a proprietary product developed by Outfoxed Pest Control), blended cat urine and faecal material, fried chicken meat, tuna oil and whole, dead, laboratory mice. Audio lures (Feline Audio Phonic, Westcare Industries, Nedlands, Western Australia) were used at many sites. Figure 5. Location of cage and leghold trap sites.
Monitoring of collared animals The status (alive or dead) of all collared animals was checked several times prior to baiting. No attempt was made to directly observe the animals during these surveys but instead relied on the mortality sensor to indicate whether the animal was alive or not. An Australis 26K VHF receiver and handheld 3 element yagi antenna (Titley Electronics, Ballina, Australia) were used to search for and assess the status of each collared animal. Most animals could be detected from locations with higher elevation within the study area. However, more intensive searching was conducted for collared animals which could not be detected from hills using an omni-directional antenna fitted to the roof of a 4WD vehicle driven slowly along the tracks within the study area. The location the VHF transmission was detected Automated cameras Automated cameras were installed at positions throughout the study area (Figure 9) to assess presence of Feral Cats and foxes prior to and following baiting (see front cover image). Cameras were set both on and off tracks. Forty- seven cameras were used in off track locations and provided with a food lure (pilchards) over a period of 14 days prior to (i.e. 6–18 April) and following (e.g. 19–31 May) application of baits. All cameras were configured to record three photos at every motion detection with no pause between detections. The location of these ‘bush’ cameras was determined using a semi-random process. The study site was partitioned into three areas (labelled A – C) based on fire history and was recorded. A thorough search was undertaken on the 8 topography. All 1 km2 where access was expected May (i.e. the day before baiting) to determine the status of each collared animal. Analysis of data collected by GPS collars was undertaken using ArcView 3.3 Geographic Information System software (ESRI, Redlands, USA) that included the Home Range Extension 1.1 (Rodgers and Carr 1998). The home range of cats was determined using the 95% Minimum Convex Polygon function. to be very difficult were ruled out and the remaining cells were numbered. A series of random three digit X and Y axis numbers that had been generated from the software program ‘R’ were fitted against each cell to form a complete geographic UTM reference.
Cat 10 – The GPS collar indicated that this cat crossed baited transects between 1520 hrs –1920 hrs on 10 May, and then also at 0721 hrs on 11 May 2011. This cat may have crossed transects several times to reach its recorded position at 1521 hrs on May 2011 or indeed could have transited along the Limestone Track to reach its position at this time (Figure 21). This cat survived. Figure 21. Location of Cat 10 while baits were attractive and palatable.
whether any cats survived consumption of a toxic bait. This assessment could ordinarily be made by assessing presence of Rhodamine B bands in facial whiskers (Fisher et al. 1999; Fisher 2000). However, the density of vegetation at the site precluded the use of VHF-guided hunting of collared cats. A similar explanation is probable with the observed impact on the population of Red Foxes with respect to expected detection at bush camera sites and choice of lure. Foxes are readily detected by automated cameras with food lures in off-track situations (Robley pers. comm.), although foxes may be more frequently detected in road locations in densely vegetated areas (Towerton et al. 2011). Preliminary trials have demonstrated that captive Red Foxes (n=4) can be poisoned with Curiosity® baits (Johnston and Gigliotti, unpublished data). The observed survival of foxes (4 of 4) in this study suggests that further research is warranted to determine the attractiveness and palatability of Curiosity® baits to free-ranging animals. 34