Distribution, behavior and diet of the Asiatic black bear in human modified landscapes

Abstract

The broad negative effects of land-use conversion for agriculture on wildlife species are well known, but few studies have evaluated how different land-use types impact spatiotemporal patterns and trophic strategy of large carnivores. We conducted sign surveys for the Asiatic black bear, a critically endangered subspecies in southeastern Iran. We applied Bayesian occupancy modelling and quantified spatiotemporal determinants of black bear occurrence as a function of date palms, distance to agriculture, elevation, precipitation, and protected area (PA) size. We also investigated its diet composition based on scat (n = 150) analyses. Date palm area size (β = 2.07; 95 % Credible Interval = 0.67 to 3.89) and distance to croplands had a strong and significant (β = −1.06, 95 % CrI = −2.10 to −0.20) influence on the occupancy. Elevation, precipitation, village density, and PA size did not substantially influence occupancy. Black bear detection probability became 100 % only above 14 km survey effort, indicating its overall rarity, and bears were much more easily detected during and after rainfall. Bears mainly relied on date palms (41 %) followed by herbaceous plants (24.6 %), insects (15 %), wild mammals (6.4 %), wild fruits (5.6 %), livestock (4.9 %) and other vertebrates (2.5 %, e.g., birds). Most of the predicted bear occupancy was outside PAs and thus suggests a high likelihood of human-bear conflicts. Presumably, resource density is insufficient to support bears inside PAs, but information concerning resource density is currently lacking. Our results showed that the agricultural landscape provided an important feeding (46 %) area for bears. Consequently, effective conservation programs such as the protection of abandoned date palm groves as a conflict-free food source are necessary. Practical training such as protective measures against crop-raiding behavior of bears would be essential to foster the tolerance of people toward bears and thus can help facilitate coexistence.