Evaluation of remote cameras for monitoring multiple invasive mammals in New Zealand

Numerous conservation projects in New Zealand aim to reduce populations of invasive mammalian predators to facilitate the recovery of native species. However, results of control efforts are often uncertain due to insufficient monitoring. Remote cameras have the potential to monitor multiple species of invasive mammals. To determine the efficiency of cameras as a multi-species monitoring tool, we compared the detection rates of remote cameras and tracking tunnels over 4 non-consecutive days across 40 sites in Wellington. On average, cameras detected significantly more hedgehogs (Erinaceus europaeus) and rats (Rattus spp.) than tracking tunnels, and their images could be used to identify rats to the species level in 50% of detections. Cameras also detected more possums (Trichosurus vulpecula) but missed recording mice (Mus musculus) on some occasions where tracking tunnels detected them, and vice-versa. We conclude that remote cameras are well-suited for simultaneously monitoring multiple species of invasive mammals in New Zealand.