Estimating fox abundance using the simultaneous count method

Abstract

Feral foxes Vulpes vulpes are a major threat to Australian wildlife and assessing the success of control programs requires comparison of abundance before and after control. While camera traps are often used to assess fox activity, estimating abundance is difficult due to the inability to distinguish individuals requiring an “unmarked” methodology. We tested the “simultaneous count method” which requires samples to be independent during the sampling period, that is, 24 h, while allowing lack of independence between sampling periods. This enables repeat detections of animals to estimate abundance. We tested the method on camera data collected over 5 years at Oolambeyan National Park, New South Wales, during a fox control program and conclude that the method has merit. We were able to statistically measure an effect of change in abundance from a median of 57 to 2, however, estimation of detectability was erratic.

Keywords

abundance / Bayesian / feral animal / Fox / unmarked

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RIGHTS & PERMISSIONS

2024 The Author(s). Wildlife Letters published by Northeast Forestry University and John Wiley & Sons Australia, Ltd.