Using automatically-triggered cameras to monitor and estimate bobcat abundance

Abstract

Advances in automatically triggered photography provide wildlife professionals with an opportunity to develop innovative applications with important management and research implications. The use of automatically triggered cameras to monitor and estimate the number of bobcats (Lynx rufus) in a population might be more useful to managers and researchers than traditional methods involving scent stations and physical capture. This study evaluated whether bobcats could be surveyed using automatically triggered cameras as part of a mark-recapture study design. I tested the assumptions that bobcats were individually identifiable by their natural markings and that information obtained from camera surveys can contribute to abundance estimates from mark-recapture calculations. The ability to identify individuals in automatic photographs was influenced by the position in which the bobcat was photographed. Bobcats were most often photographed perpendicular to and facing toward the camera, which enhanced the observer's ability to identify unique pelt and facial markings. Individual bobcats were successfully identified using these natural markings. Scent stations and physical capture combined with radio telemetry were unable to monitor changes in abundance or provide abundance estimates, whereas automatically triggered camera surveys provided reasonable and reliable abundance estimates. Residence status of some individuals was determined by frequency and timing of photographic capture. Camera surveys provided a reliable framework in which to conduct mark-recapture surveys. Further research to refine the technique for bobcats and expand its applications is encouraged.