Summary: | Thesis (Ph.D.), Environmental and Natural Resource Sciences, Washington State University Preventing wolf-livestock conflicts requires identifying conditions placing livestock at risk and focusing outreach and adaptive management at a local scale. Risk mapping has become a popular tool to predict and display livestock depredation risk by carnivores worldwide. To date no maps predicting livestock depredation risk exist for the Northern Rocky Mountain gray wolf (Canis lupus) population. Historical (i.e. 1991 – 2008) data from Idaho and Montana were used to predict cattle depredation risk by gray wolves recolonizing Washington. Risk models were developed at two spatial scales, (1) wolf pack territory (n = 137) and (2) cattle grazing allotment (n = 69) to test hypotheses that cattle depredations by wolves were associated with wolf demographics, cattle and wild prey abundance, allotment characteristics, and land cover types. Within wolf pack territories, cattle depredation risk increased as cattle abundance and adult wolf removal increased and if the pack depredated the previous year. Adult wolf removal and pack size showed weaker evidence in their relationship with cattle depredation probability and the predicted number of cattle depredated. Similarly, cattle depredation risk increased for larger grazing allotments with more cattle, wolves, and grassland cover and decreased with pack reproduction and a later cattle turnout date. Wolf pack reproduction, cattle turnout date, and percent grassland cover indicated high variability in the direction of their relationship with cattle depredation probability and the predicted number of cattle depredated. Forecast maps for Washington identified hotspots of high (81 – 90%) depredation risk in Yakima, Kittitas, and Columbia counties. Cattle grazing allotments only occur east of the Cascade Mountains, and hotspots in Okanogan, Ferry, and Yakima counties were recognized as intermediate (61 – 80%) depredation risk. These risk models and maps provide locations to focus depredation prevention measures and a template for future analyses as wolves continue to recolonize Washington. Washington State University, Environmental and Natural Resource Sciences
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