Colorado plans to reintroduce wolves by the end of 2023. The proposal was tentatively given the green light by the US Fish and Wildlife Service, which issued a draft statement of approval.
In their draft decision, the US Fish and Wildlife Service wrote that Colorado can establish what’s called a “nonessential experimental population”—a designation for groups on which the entire species’ survival doesn’t depend. This will allow for control of the gray wolf population within Colorado and provide conservation of the species. The Colorado plan falls under the Endangered Species Act of 1973, in the section devoted exclusively to species recovery.
Gray wolves, the largest living canine species, are endangered in almost all of the United States and Mexico. As a keystone predator—a species that is disproportionately responsible for the populations of other species—the gray wolf “is an integral component of the ecosystems to which it typically belongs,” according to the US Fish and Wildlife Service.
And as it turns out, wolves might also be an unlikely buffer for a growing threat: climate change.
“Wolves had been pursued with more determination than any other animal in United States history.”
The Yellowstone Experiment
After a court order in 2022, gray wolves were declared endangered in 48 states and Mexico—though a group of wolves persisted in Colorado. Known as the Northern Rocky Mountain wolf (or the Northern Rocky Mountain timber wolf), this subspecies of the gray wolf is native to the Northern Rocky Mountains.
In the rest of the state, however, wolves have mostly been killed off in their natural habitat. And bringing them back will lead to the return of other species.
This has happened before. The most famous example is the 1995 reintroduction of wolves into the Greater Yellowstone Ecosystem. Packs of hunting wolves were prolific in Yellowstone National Park when the park was first established in 1872. By the 1920s, the once flourishing wolves had been hunted to near oblivion. As Outside wrote, “Wolves had been pursued with more determination than any other animal in United States history.” In 1974, the gray wolf was first declared endangered on the initial version of the Endangered Species Act.
When biologists reintroduced the first group of wolves, eight from Jasper National Park in Alberta, Canada, back to the park, elk were rampant in Yellowstone. In their grazing habits, the elk killed huge numbers of trees and plants. According to Outside, “As early as the 1930s, scientists were alarmed by the degradation and were worried about erosion and plants dying off.”
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The impact of wolves resonates through an ecosystem.With the new wolves as predators, the elk population was controlled, protecting the open valleys and plants. Defenders of Wildlife wrote, “With less grazing pressure from elk, streambed vegetation such as willow and aspen are regenerating after decades of overbrowsing.” More and older trees created a habitat for beavers, fish, and birds to flourish. With its keystone predator returned, Yellowstone’s ecosystem became healthier in ways even beyond what the biologists had hoped. Pronghorn antelope and red foxes returned, as the wolves kept the park’s coyote population in check.
Wolves as a Buffer
How does this relate to climate change? The impact of wolves resonates through an ecosystem, creating more resiliency to climate threats.
Climate change means an earlier winter thaw, which means less winter carrion for animals that rely on those carcasses to survive, like hawks, vultures, and foxes. Scientists call this a “food bottleneck.” But with their hunting behavior, wolves generate carrion that becomes food for many scavenger animals currently at risk. In this way, wolves can act as a “buffer” against the worsening impacts of climate change for these vulnerable scavenger animals, providing them with food and helping them more readily deal with a changing environment.
Along with alleviating the strain of climate change on the food supply, wolves also have an influence on the carbon cycle. The Natural Resources Defense Council gives an example of this with wolves and moose. Wolves “directly influence both the foraging behavior and abundance of moose through predation—which changes the way moose interact with boreal plant communities—which alters the forest composition and increases tree biomass—which then enhances carbon storage in both plants and soils.”
Protests and Management
In the snowy winter of 1995, the wolves were carried into Yellowstone on bobsleds.
Despite their benefits to the ecosystem and a rapidly changing climate, bringing back wolves is controversial. The wolves in Yellowstone preyed on more elk than expected. As feared, they also traveled into neighboring Montana, where the pack’s alpha male was illegally shot and killed. Ranchers protested the move by Colorado when the plan to reintroduce the predators was first announced more than two years ago, fearing livestock loss.
Currently, Colorado’s reintroduction plan includes an allowance for ranchers to shoot wolves should the predators be found in the act of killing livestock or pets. State wildlife officers would also be able to kill wolves preying on livestock, elk, or deer in excessive amounts as part of the wolf management plan. Colorado Public Radio has reported that Colorado plans to bring the wolves in from other western states, including Washington, Oregon, and Idaho’s Nez Perce Tribe.
In the snowy winter of 1995, the wolves were carried into Yellowstone on bobsleds. That may not be possible in the future. Our winters across the globe are changing, with less snow, warmer temperatures, and earlier thaws. But wolves, a keystone predator once nearly hunted out of existence, can help.