Cause-and-Effect: Wolf Reintroduction

The notion seemed to emerge almost incidentally during a conversation with Chris O’Bryan: “That could be an intriguing thought experiment,” he remarked, suggesting that the reintroduction of wolves in Colorado might actually benefit the state’s cattle industry.

O’Bryan, a postdoctoral fellow at the University of Queensland in Australia, has dedicated much of his career to examining the unforeseen consequences of reintroducing large predators into ecosystems. His 2018 study, published in Nature Ecology and Evolution, analyzed the impacts of leopards in India, red foxes in America, and falcons in New Zealand, among others. However, he acknowledges that tracking the effects of these animals on their environments can be challenging.

The proposal to reintroduce wolves to Colorado—initiated by a ballot measure narrowly approved by Colorado voters in November—offers some well-known advantages: wolves prey on deer, potentially reducing deer-auto collisions and controlling deer-borne diseases like Lyme disease. But it was a reference to dingoes in Australia that caught O’Bryan’s attention.

“Deer and elk directly compete with domestic herbivores—such as cows,” he explained. According to O’Bryan’s research, dingoes help regulate populations of red kangaroos, Australia’s most abundant native herbivore and a significant competitor for grazing space with cattle. By preying on kangaroos, dingoes have inadvertently facilitated grazing for cattle. While the occasional dingo may target a cow directly, O’Bryan’s study suggests that overall, dingoes have enhanced pasture productivity and profitability.

Could a similar dynamic emerge with Colorado’s reintroduced wolf population? Elk, in particular, compete with cattle for grazing space in the state and are a primary food source for wolves. However, O’Bryan cautions that, like many cause-and-effect scenarios, definitive conclusions can only be drawn through observation.

According to Colorado Parks and Wildlife, human overhunting of elk and deer led gray wolves, once abundant statewide, to shift their focus to livestock. Consequently, wolves were eradicated from the state by the 1940s. Before Election Day, concerns about potential impacts on cattle were a major argument against wolf reintroduction.

Michael Robinson, a conservationist with the Center for Biological Diversity, is skeptical about the applicability of the Australian study to Colorado, suggesting that it is more often cattle that displace elk from grazing lands, rather than vice versa.