A pilot study of a novel method to monitor weasels (Mustela nivalis) and stoats (M. erminea) in Britain.

Weasels (Mustela nivalis) and stoats (M. erminea) are considered to be widespread and common in Britain, but little is known of their abundance and population trends outside game estates, and there is currently no reliable, cost-effective method to monitor the two species across their range other than by seasonal, localised kill-trapping. We conducted a pilot study to determine the efficacy of a novel method for detecting the presence of live weasels and stoats in Britain. We trialled the ‘Mostela’, a wooden box comprising a plastic tunnel and a camera trap, at three sites in England. Weasels were detected at all three sites, with the time to an initial detection at a site ranging from 16 to 54 days. Stoats were detected at one site. Overall, a high number of trap nights was required to achieve a relatively low number of detections. Nevertheless, the method shows potential for future surveys and associated research, particularly on weasels.