The value of camera traps in monitoring a feral-cat and fox reduction program

Abstract

Abstract ContextWe examined the effectiveness of camera traps to monitor the success of a feral-cat (Felis catus) and fox (Vulpes vulpes) reduction program near Ravensthorpe, Western Australia. AimsTo determine whether camera traps are an effective tool to measure a reduction in the abundance of F. catus and V. vulpes at a local scale. MethodsIn all, 201 Foxoff® baits (i.e. 1080) were laid along the edge of unsealed tracks for each of three periods (i.e. opened 13–15 May 2017, Period 1 closed 29–31 May 2017, Period 2 closed 12–13 June 2017, Period 3 closed 25–26 June 2017), and 98 bait sites were monitored by camera traps during each period. In addition, 150 baited cage traps were deployed to catch F. catus for the same three periods. Vulpes vulpes and F. catus were also shot in the adjacent paddocks before traps were opened and during the laying of traps and bait replacement. We used the first 13 days of camera-trapping data for each period to examine whether there was a significant reduction in V. vulpes and F. catus. Key resultsCamera traps recorded a significant reduction in V. vulpes images, but knock-down with Foxoff® baits was not as effective as in other programs, and there was no change in the measured abundance of F. catus. Numerous baits were taken and not recorded by camera traps. Multiple V. vulpes moved past or investigated, but did not take baits and a V. vulpes was recorded regurgitating a bait. ConclusionsCamera traps were not effective for recording bait-take events. Vulpes vulpes knock-down was low and slow compared with other studies, did not reflect the number of baits taken and Foxoff® baits appeared unpalatable or unattractive to many V. vulpes. ImplicationsCamera traps did not record a high proportion of bait-take, appeared to be insensitive to small changes in fox and cat abundance and Foxoff® baits were less effective in reducing the abundance of V. vulpes than in other studies.