Scent lures and baits at camera traps improve time to first detection and detection probability of two typically elusive species of weasel

Abstract

There is a growing body of evidence that weasel species are in decline globally. More data on their ecology and distribution are needed to plan and justify any conservation management actions. Camera trapping can be an effective survey method for many species; however, the small size and quick movements of weasels present challenges in detection and little consensus exists on practices for attracting them to improve detection. This study tested different combinations of meat baits and scent and audio lures to assess the most effective methods. Camera traps were set up in clusters of three at 42 sites to test the effectiveness of these combinations, accounting for season, in terms of the time to first detection (TFD), detection probability using occupancy models, and the number and clarity of weasel photos. We also repeated TFD and detection probability analyses for setups that were ≥ 20 m apart in case of overlap of effects. The average TFD across all sites was 43 days. Fall typically had the shortest TFD with beaver bait in fall achieving the best results. After accounting for occupancy, predicted detection probability across a 60-day survey was highest in fall with the best combination being salmon lure and beaver bait. The treatment type did not impact the average number of photos captured, but the clarity of photos was significantly positively related to use of bait and lure, type of lure, and specific combinations of bait and lure.