The gray wolf prefers to eat fleet ungulates—elk, deer—but when Europeans arrived in America with livestock its menu expanded.

A wolf that cannot find its favored meal may turn to cattle and sheep. Livestock producers and big-game hunters have considered wolves an existential threat since Colonial days. In 1634, a tract called “New England’s Prospect,” by William Wood, described the animals as “the greatest inconveniency,” noting that there was “little hope of their utter destruction, the Countrey being so spacious, and they so numerous.”