A preliminary density estimate for Andean bear using camera-trapping methods

Abstract Andean (spectacled) bears (Tremarctos ornatus) are threatened across most of their range in the Andes. To date no field-based density estimations are available for this species. We present a preliminary estimate of the density of this species in the Greater Madidi Landscape using standard camera-trapping methods and capture–recapture analysis. We photographed 3 individually recognizable Andean bears in a 17.6 km2 study area spanning 4 adjacent high elevation humid Andean valleys during August–September 2004. Capture–recapture statistics estimated an abundance of 3 bears; plausible geographic buffers yielded density estimates of 4.4 or 6 bears/100 km2. We recommend that future camera-trapping studies on this species sample larger areas over longer periods and use 3 camera trap units at each station.