Occupancy and habitat use by the Andean bear are negatively affected by human presence and forest loss

Abstract

Protected areas require methodologies to monitor the status and effectiveness of species management strategies. In this work, single-species, single-season occupancy models were employed to estimate the occupancy and habitat use of the Andean bear in the Tatamá National Natural Park through a nested design of 1 km2 cells inserted in 16 km2 cells. The occupancy at 16 km2 was ψ16 = 0.89 (E.E. = 0.06), with a detectability p = 0.405 (E.E. = 0.039). When examining the factors influencing the habitat use of the Andean bear at the 1 km2 scale, the four most suitable models for calculating use indicated a most negative relationship between use and the percentage of human activities in the cell (βHA = −1.46 [E.E. 0.61]). Additionally, bear use was found to have the most positive relationship with the forest proportion in the cell (βF = 16.59 [E.E. 13.55]) and Euclidean distance to population centers (βDPC = 1.05 [E.E. 0.82]). These findings allowed for adjusting the Prevention, Surveillance, Control, and Monitoring programs and identifying areas requiring forest cover restoration. The sampling design and effort implemented is able to detect a 25% reduction in occupancy with a statistical significance of α = 0.2 and a statistical power of 1 − β = 0.8.