Effects of translocation on survival of nuisance bears

Effective mitigation of human-wildlife conflict should aim to reduce conflicts while also minimizing wildlife mortality. Translocation is often used to mitigate human-wildlife conflict but translocated individuals may have reduced survival, which could negatively affect population growth and social acceptance of translocation as a management tool. Yet, non-translocated nuisance individuals may also have low survival due to inherent risks associated with nuisance behavior. We used a 38-year dataset of 1233 marked and translocated nuisance American black bears (Ursus americanus) as a model system with which to evaluate the impacts of translocation on nuisance bear survival. We used multi-state mark-recapture models to estimate annual harvest and non-harvest mortality rates and tested for effects of translocation distance and harvest rate on recapture and both mortality rates. Recapture probability increased with translocation distance but 75% of translocated bears were translocated <= 75 km and recapture probabilities were <0.05 across these distances. Survival was 0.43 for adult males, 0.56 for adult females, and 0.38-0.40 for yearlings. However, increasing translocation distance reduced both harvest and non-harvest mortality (beta = -0.0044, 95% CI = -0.0081 to -0.0006 and beta = -0.0020, 95% CI = -0.0051 to 0.0011, respectively) showing that increasing translocation distance does not negatively impact survival. Our survival estimates were generally lower than those reported for non-nuisance American black bear populations (0.67-0.83), which likely reflects risks associated with nuisance behavior, such as proximity to human dwellings, agriculture, or roads which in turn may increase harvest and/or road mortality. Our results show that translocation is a useful approach for mitigating human-bear conflict that does not always negatively affect survival. Lower survival of nuisance bears suggests that biologists should focus efforts on reducing the incidences of human-wildlife conflicts (e.g., removing anthropogenic food sources).