The Hidden Ways Wolves Keep an Ecosystem Healthy

Wolves almost always get a bad rap, thanks to everything from fairy tales and fables to modern movies depicting the animals as bad guys lurking in the shadows.

In reality, wolf attacks on humans are extremely rare.

“In North America, you can count the number of fatal attacks by wolves on people on one hand,” says Bertie Gregory, National Geographic Explorer and host of Wolves Up Close with Bertie Gregory, premiering November 6 on National Geographic, Disney+, and Hulu. “And in my experience spending time with them, wolves either want absolutely nothing to do with us, or they’re just sort of curious.”

The wildlife filmmaker has been following a single pack of wolves off and on for eight years. And because wolves typically only live two to three years in the wild, he’s seen all the animals he once knew in this pack pass on and be replaced by their offspring.

“These wolves live in Hudson Bay, Canada, and they live in a very remote area where they are not hunted,” explains Gregory. “They don’t see people particularly often, and so they don’t have this fear of us like they do in places where they’re aggressively persecuted, which is most of North America.”

Among the facts Gregory reveals in the new television special are the many ways wolves contribute to a healthy ecosystem—ways that may surprise viewers who grew up with the idea that the only wolves out there were the big-and-bad, huff-and-puff variety.

“A healthy wolf population means a healthy planet, and that also means healthy people,” says Gregory. “I’m in awe of them.”

Boosting Biodiversity and Keeping Landscapes Diverse

At one point during Gregory’s new show, his team stumbles upon a moose carcass that had been left by the local wolf pack. Wisely, the crew sets up camera traps nearby to see what other animals might be making use of the fresh kill.

“As soon as the wolves left the kill, we started seeing that same carcass supporting so many different, smaller animals, from pine martins to foxes, wolverines, ravens, and even lone wolves that weren’t part of the pack,” says Gregory of the footage. “It was just a perfect example of how many other species rely on them.”

(California's Wolves Have Returned After a Century. But at What Cost?)

And it’s not just birds and mammals. Carcasses mean a boom for carrion and burying beetles, rove beetles, wasps, flies, ants, and many other invertebrates.

“The longer that carcass degrades, you also then get nutrients leached into the soil,” says Sean Johnson-Bice, a research scientist at the University of Minnesota.  

Eventually, trees and other plants make use of those nutrients, turning kill sites into hotspots for all kinds of biodiversity.

Maintaining Prey Populations

Up in Hudson Bay, there aren’t many animals that can compete with a 1,500-pound moose. But the same is also true for elk, deer, bison, and the many other animals wolves prey upon across their range.

“I certainly wouldn’t want to be a moose with a limp around those guys,” Gregory jokes about the wolfpack he filmed.

While every predator and prey interaction is complicated—the dynamics depend on the habitat type, the number of animals any given ecosystem can support, and the species involved—apex predators are generally considered beneficial to the food web.

“Without wolves, the herbivore population begins to overgraze the landscape,” says Gregory.

In Yellowstone National Park, for instance, scientists have found evidence that the reintroduction of wolves contributed to the recovery of willow and aspen trees and overall habitat diversity by reducing the population of elk. Less grazing due to fewer elk in turn led to improved habitat quality for animals like songbirds and beavers.

Changing the Behavior of Other Animals

Killing prey species isn’t the only impact wolves have, however.

“Their very presence creates a landscape of fear,” says Gregory. “Herbivores spend less time in places that have good foraging habitat but are actually very risky places to be, such as riverbeds. By causing them to move more, countless other species of plants and animals thrive.”

In a 2023 study published in Proceedings of the Royal Society B: Biological Sciences, Johnson-Bice and his colleagues showed that by preying upon beavers, wolves could indirectly alter the trajectory of an entire forest. This is because beavers reduce tree cover and create wetlands, which are ecological hotspots in their own right.

What’s more, beavers that foraged farther from home were more likely to get killed by wolves, which means that the wolves applied selective evolutionary pressure on the bucktoothed ecosystem engineers.

“It all comes down to this idea of landscape heterogeneity,” says Johnson-Bice, referring to the ecological concept that landscapes with mixtures of species and physical variations are healthier than those where everything stays the same.

(Inside the sacred wolf hunts of western Mongolia.)

Whether it’s drawing in wolverines and ravens to a kill site, boosting nutrients in the soil, creating a hotspot for decomposing beetles and flies, disrupting and reducing large herbivores, or directly changing the way beavers affect an area, the presence of wolves can have wide-ranging impacts on an ecosystem that, frankly, scientists are still trying to quantify.

“They are just so special,” says Gregory. “And on an emotional level, we have such love for dogs. It seems totally bizarre to me that their wild relatives don’t get the same respect.”