The wolves of Yellowstone National Park are perhaps the most recognizable conservation success story in America. Native wolves were exterminated in the park by the 1920s — shot and poisoned as part of official park policy. After decades of conservation campaigns, they were reintroduced in 1995. Since then, they have become a poster child for a sometimes controversial brand of nature conservation called “rewilding” that puts the emphasis on handing the reins over to nature.

But does the return of the wolves represent a return to “nature”?

“The term ‘natural’ — it’s just really hard to get any agreement on what it means,” says Rolf Peterson, an ecologist at Michigan Technological University. Peterson studies wolf populations in Yellowstone and elsewhere in the United States.

Because the wolves prey on large, grazing animals like elk, researchers have attributed the recovery of trees like aspen and willow in some areas of the park to the reintroduction, though a straightforward connection has been hard to prove. As rewilding has gained traction over the past two decades, the concept has also expanded. The term “rewilding” is now sometimes used as a catch-all for efforts to rehabilitate an ecosystem, which dilutes its original intent, says Francisco Santiago-Ávila, a program manager with Project Coyote and the Rewilding Institute, a non-profit dedicated to promoting rewilding as a means of conservation around the globe. Nevertheless, the movement retains a focus on protected areas and large, charismatic animals.

“Rewilding recognizes that nature itself has autonomy — that non-human individuals have agency, and that, therefore, we should limit our control over them,” says Santiago-Ávila.

The Three Cs

Rewilding was originally conceived as an alternative to “traditional” conservation, which saw nature as a resource to be used by people, says Santiago-Ávila. The term itself was coined in 1992 by environmental activist Dave Foreman, and the biologists Michael Soulé and Reed Noss later expanded on the concept.

Their vision was based on three “Cs”: bringing back large, majestic carnivores, creating core wilderness areas where those animals can live and thrive, and developing corridors to allow animals to pass between these areas. This idea of “continental-scale protection of nature” is echoed in the recent Yellowstone-to-Yukon initiative, which aims to protect habitat and wildlife over a roughly 2,100-mile stretch of the Rocky Mountains, says Santiago-Ávila.

“I feel like all this focus on the past is a turnoff for people.”

Some projects bring in “surrogate” species to replace those that have gone extinct. For instance, on the Dutch nature reserve Oostvaardersplassen, domestic cattle play the role of the mighty, vanished aurochs. Others have even explored the possibility of “de-extinction,” or resurrecting, Jurassic-Park-style, species like the wooly mammoth.

Rewilding proponents often point to the ecological benefits of bringing back lost species. But projects like de-extinction also hint at the movement’s moral dimensions — a desire to bring back a wilder world that humans have destroyed.

For some, this message seems like a losing strategy. “I feel like all this focus on the past is a turnoff for people, because you’re basically conveying the message that the current world is trash and not worth protecting,” says Michelle Marvier, a professor of environmental studies and sciences at Santa Clara University. Marvier likes to visit a salt pond near her home, a human-engineered landscape that hosts a wide variety of birds. Places like this are worth preserving, too, says Marvier, even if they are not “wild.”

Besides, humans have changed the planet so drastically that some goals might be out of reach. “It’d be cool to have elephants and camels roaming around North America…but the climate has changed so much,” says Marvier. “You’re trying to restore something that I don’t think can possibly exist in today’s world.”

Giving up control

An emphasis on “people-free nature” can have dire consequences. Last December, members of the United Nations pledged to protect 30 percent of the world’s land and water. In the years to come, lawmakers will need to figure out exactly what that protection will look like. But the “30 by 30” declaration has renewed fears that governments will force people out of their homes in the name of conservation. The large majority of the world’s remaining species are concentrated in lands occupied by indigenous people, mostly in tropical areas like the Amazon rainforest. People like the San of southern Africa have been violently relocated and excluded from their traditional lands and hunting grounds over concerns that they would harm wildlife.

For industries like logging and mining that exploit natural resources in rural areas, coexisting with free-roaming animals — and the legal protections that sometimes come with them — can be a headache. In the wake of a campaign to reintroduce beavers to Great Britain, some farmers have claimed their fields were flooded by rogue beaver dams.

But there are other places where a human touch may ultimately benefit some rewilding efforts and benefit the local ecosystem without affecting humans directly — for example, the reintroduction of wolves on Isle Royale, an island on Lake Superior.

“If we allow them to, [the wolves] will take care of things.”

The Isle Royale wolves originally crossed to and from the island via an ice bridge that formed over the water in most winters. But a warming climate toward the end of the 20th century meant there were many years when the bridge didn’t appear. The wolves became isolated and began to experience what’s called “inbreeding depression,” a loss of genetic diversity which reached the point of crisis when the population fell to just two wolves in 2016.

Practically all of the island is designated as a national “wilderness area.” The National Park Service has traditionally taken a hands-off approach to managing these areas in the spirit of keeping them free from human influence. But the wolves’ plight was the result of something else unnatural: anthropogenic climate change. In this case, a human touch was needed to make the island “wild” again.

Ecologist Rolf Peterson and others successfully brought more wolves onto the island, and since the first group was transplanted in 2018, the population has grown to 28 per a survey in 2022. Peterson expects some of the same results seen at Yellowstone, though things may not go exactly according to plan.

“The wolves are also killing each other, because that’s what they do,” says Peterson. Letting the wolves roam free has meant giving up a certain amount of control. “If we allow them to, they will take care of things,” he says.