Andrea T. Morehouse, Mark S. Boyce
Ursus 28 (1), 66-80, (1 July 2017) https://doi.org/10.2192/URSU-D-16-00026.1
KEYWORDS: Alberta, diversionary feeding, grizzly bear, human–wildlife conflict, intercept feeding, livestock, supplemental feeding, Ursus arctos
Supplemental and diversionary feeding can reduce conflicts between wildlife and people. However, feeding also can increase species abundance, survival, and reproductive success, which might increase human–wildlife conflicts. In southwestern Alberta, Canada, the provincial government fed road-killed ungulates to grizzly bears (Ursus arctos) each spring during 1998–2013 attempting to reduce spring depredation of livestock by grizzly bears. We used non-invasive genetic sampling, remote trail cameras, and complaint records to evaluate the efficacy of Alberta's intercept-feeding program. We monitored 12 intercept-feeding locations in 2012 and 2013. Using DNA, we identified 22 grizzly bears (19 M, 3 F) at the intercept-feeding sites. Remote trail cameras detected grizzly bears at all intercept-feeding sites, but detected females with dependent offspring at only 4 of the 12 sites. We reviewed complaint data for incidents before, during, and after the intercept-feeding program. We defined an incident as a situation where the grizzly bear caused property damage, obtained anthropogenic food, or killed or attempted to kill livestock or pets. Spring (1 Mar–15 Jun) grizzly bear–livestock incidents did not decrease during the intercept-feeding program (pre: 1982–1995, x̄ = 0.8 spring livestock incidents/yr, SE = 0.3, during: 1999–2013, x̄ = 3.3 spring livestock incidents/yr, SE = 1.3, t = 1.76, 27 df, P = 0.09). We also collected DNA samples from bears involved in incidents, and only 2 bears detected at intercept-feeding sites were detected also at a spring incident site. The intercept-feeding program was suspended in 2014 and 2015, and we did not detect an increase in spring livestock depredation. We estimated annual operating costs to be $43,850 Canadian dollars (CAD); initial capital equipment investment was $19,000 CAD. In total, approximately $720,600 CAD has been spent on the intercept-feeding program between 1998 and 2013. Intercept feeding did not decrease spring livestock depredation; therefore, other mitigation efforts, including electric fencing and deadstock removal, might be a more cost-effective long-term solution.