A study from the University of Montana shows that when wolves attack cattle, it can cause calves to gain less weight.
Report co-author Derek Kellenberg says his team found that when wolves were simply in the area, there was no change in cattle weight, but that on ranches where there was a kill, the cows weighed less.
Kellenberg says skinnier cows are worth less, so ranchers can lose thousands of dollars.
But he says wolf predation was not the biggest factor affecting weight.
“Snowfall, rain, temperature, as well as ranch-specific geography and husbandry practices, explained the vast majority of the variance in cattle weights over time,” Kellenberg said. “So the wolf effects tended to be small, but for those ranches that experienced an actual depredation, they weren’t inconsequential.”
Ranchers can get reimbursed when they lose a cow to wolf depredation, but Kellenberg says the amount only covers the animals that are killed, not the indirect costs on the rest of the herd.