Population estimates of an endangered rock-wallaby ('Petrogale penicillata') using time-lapse photography from camera traps

Abstract

Camera trapping techniques, in combination with robust population estimators, can provide estimates of animal abundance. Here we use a novel technique for estimating the abundance of an endangered macropod. Time-lapse photographs from camera traps were used to derive minimum known-to-be-alive (MKA) estimates for the brushtailed rock-wallaby ('Petrogale penicillata'), at Green Gully, Oxley Wild Rivers National Park in northern New South Wales, and contrasted with individual recognition estimates from still photographs taken with a single lens reflex (SLR) camera. On average, time-lapse photography returned estimates 32.5% lower than those achieved through SLR photography. However, we did not consider this an adverse issue due to the small number of animals present within each colony. In addition, the time-lapse photography data provided insight into the activity profiles of animals. Time-lapse photography has the capacity to provide relative abundance data that are of comparable accuracy and precision to other ground-based techniques, such as mark-recapture based on SLR photography.