Loss of anti-predator behaviors in cattle and the increased predation losses by wolves in the Northern Rocky Mountains

Florcke, Cornelia; Grandin, Temple

Managing livestock near Yellowstone National Park has become an increasing challenge since conservation of wolves restricts ranchers from interfering. Even though wolves are beneficial for the ecosystem, rising predation incidences on livestock (depredations) create animosity in local farmers. Temperament selection of cattle, measured by the facial hair whorl pattern (HW)1, occurred during the last 15 years and the industry prefers calmer temperament animals. Six HWs occur in cattle (high, middle, low, abnormal, multiple and none), which are mutually exclusive and can be identified by using the eye-line as a reference point. We analyzed depredation of calves near Council, ID in 2011. A herd of 588 Black Angus × Charolais crossbreds (age range: 5 - 17 years) was observed. By analyzing the HW and age of cows in relation to depredations, we could identify a connection between these three factors (P < 0.001). The HW of a cow influenced the probability of losing the calf to predation (P < 0.001). Cows without the facial HW faced an increased percentage of losses (probability of 19.6% of losing the calf) compared to other HW (probability between 0% - 6.1%). An age effect on the probability of losing the calf was also found (P = 0.023). Cows over the age of 10 years are more likely to lose their calves. Our findings suggest that behavioral differences between cows with different HWs exist. Differences in protectiveness or vigilance towards the surroundings in cows without a facial HW may lead to an increased probability of losing their calves.