Crying Wolf? A Spatial Analysis of Wolf Location and Depredations on Calf Weight

摘要

Combining a novel panel dataset of 18 Montana ranches with spatial data on known wolf pack locations and satellite-generated climatological data from 1995-2010, we estimate the spatial impact of changing wolf pack locations and confirmed wolf depredations on the weight of beef calves. We find no evidence that wolf packs with home ranges that overlap ranches have any detrimental effects on calf weights. Other non-wolf factors, notably climate and individual ranch-specific husbandry practices, explained the majority of the variation in the weight of calves. However, ranches that experienced a confirmed cattle depredation by wolves had a negative and statistically significant impact of approximately 22 pounds on the average calf weight across their herd, possibly due to inefficient foraging behavior or stress to mother cows. For ranches experiencing confirmed depredation, the costs of these indirect weight losses are shown to potentially be greater than the costs of direct depredation losses that have, in the past, been the only form of compensation for ranchers who have suffered wolf depredations. These results demonstrate a potentially important and understudied aspect of economic conflict arising from the protection and funding of endangered species recovery programs.