Evaluating the effectiveness of a feral cat control operation using camera traps

Abstract

Feral cats (Felis catus) have a negative impact on native biodiversity in New Zealand. As such, their populations require careful management and monitoring of the effectiveness of these management operations. We used camera traps to assess (1) effectiveness of an intensive cat control operation, and (2) the level of reinvasion six months later. Cat abundance was estimated on a pastoral property in Hawke’s Bay, North Island, New Zealand, subject to cat control using trapping and shooting. Forty cameras were placed on a grid with 500 m spacing and deployed for a total of nine weeks: (1) pre-control, (2) immediately post-control, and (3) six-months post control. Cat abundance was estimated using an index-manipulation-index (IMI) method. The IMI method estimated an c. 84% decrease in cat abundance immediately post-control, suggesting the operation worked well at removing most resident cats at this site. The detections observed six months later suggest reinvasion was very low.