Comparison of camera traps and kill traps for detecting mammalian predators: a field trial

Abstract

Currently there are few robust techniques being used in New Zealand to assess the results of pest control targeting predatory mammals such as stoats (Mustela erminea), feral cats (Felis catus) and hedgehogs (Erinaceus europaeus), with most operations using capture rates from kill traps as a measure of success. We conducted field trials of camera traps to detect these species at two sites—Macraes Flat and Tasman Valley—where intensive predator trapping is conducted by the New Zealand Department of Conservation. We compared camera traps with kill traps in terms of capture rate per 100 trap nights. Camera traps detected all three target species, as well as various non-target animals. Capture rates of cats and hedgehogs were higher with cameras than with kill traps. Comparisons for stoats were inconclusive due to a low number of detections. We suggest that camera traps are suitable for monitoring relative abundance of cats and hedgehogs, and recommend further testing in areas of higher stoat abundance.