After Gray Wolves Reintroduced Into Yellowstone, Something Amazing Happened to the Ecosystem

After Gray Wolves Reintroduced Into Yellowstone, Something Amazing Happened to the Ecosystem
(Getty Images | POOL)
2/14/2020
Updated:
2/14/2020

Yellowstone National Park is the largest park of its kind in the world. But it hasn’t always looked the way it does today, and that’s because Yellowstone isn’t just a national park; it’s the site of an extraordinary experiment.

In 1995, the U.S. Fish and Wildlife Service and a team of Canadian biologists captured 14 wolves from Jasper National Park in Alberta, Canada, for reintroduction to Yellowstone. It was the first time that gray wolves had inhabited this terrain since their extermination in 1926.

Things were about to get interesting.

A coyote keeps pace with a car in Yellowstone National Park, 2012. (©Getty Images | <a href="https://www.gettyimages.com.au/detail/news-photo/coyote-keeps-pace-with-a-car-as-it-runs-down-the-road-news-photo/153665876">KAREN BLEIER/AFP</a>)
A coyote keeps pace with a car in Yellowstone National Park, 2012. (©Getty Images | KAREN BLEIER/AFP)
U.S. Fish and Wildlife Service Director Mollie Beattie (L), US Interior Secretary Bruce Babbitt (2nd R), Yellowstone Superintendent Mike Finley (2nd L), and Yellowstone foreman Jim Evanoff (R) carry the first relocated wolf up to its pen in Yellowstone National Park, Wyoming (©Getty Images | <a href="https://www.gettyimages.com.au/detail/news-photo/fish-and-wildlife-service-director-mollie-beattie-us-news-photo/51969527">POOL/AFP</a>)
U.S. Fish and Wildlife Service Director Mollie Beattie (L), US Interior Secretary Bruce Babbitt (2nd R), Yellowstone Superintendent Mike Finley (2nd L), and Yellowstone foreman Jim Evanoff (R) carry the first relocated wolf up to its pen in Yellowstone National Park, Wyoming (©Getty Images | POOL/AFP)
The National Park Service explains that in the late 1800s, settlers and their livestock moved westward and suddenly had to contend with native predators, such as wolves.

To protect their livestock, settlers practiced “predator control,” and the park lost a huge number of its wolf, cougar, bear, and coyote populations. Gray wolves disappeared completely.

Yellowstone National Park employees guide a mule-driven sled carrying eight gray wolves to their release site. (©Getty Images | <a href="https://www.gettyimages.com.au/detail/news-photo/yellowstone-national-park-employees-guide-a-mule-driven-news-photo/51969528">POOL/AFP</a>)
Yellowstone National Park employees guide a mule-driven sled carrying eight gray wolves to their release site. (©Getty Images | POOL/AFP)
The park was wolf free for seven long decades, but their intentional reintroduction gave scientists the rare opportunity to study what happens when a top predator returns to an ecosystem. The gray wolves were brought in to manage the elk population, which had spiraled out of control since their main predator disappeared, says the BBC. But the wolves ended up achieving that and much, much more.
“Each wolf was radio-collared as it was captured in Canada,” reported the National Park Service. “While temporarily penned, the wolves experienced minimal human contact. Approximately twice a week, they were fed elk, deer, moose, or bison that had died in and around the park.”

The wolves, after getting used to their new surrounds and developing a taste for Yellowstone elk, were released into the park.

“Wolf #10 was the first one to run free in Yellowstone for 70 years,” regaled Kirsty Peake, the UK Wolf Conservation Trust’s advisor, speaking to the BBC. “I can feel the lump in my throat saying that!”
Bison rest on the bank of the Madison river at Yellowstone on May 11, 2016. (©Getty Images | <a href="https://www.gettyimages.com.au/detail/news-photo/bizons-rest-on-the-bank-of-the-madison-river-at-yellowstone-news-photo/532612616">MLADEN ANTONOV/AFP</a>)
Bison rest on the bank of the Madison river at Yellowstone on May 11, 2016. (©Getty Images | MLADEN ANTONOV/AFP)
But then, tragedy struck. “As feared,” Yellowstone park officials documented on their website, “#10, the alpha male, almost immediately headed north and crossed the border to Montana. His mate, pregnant with pups, followed him soon after.”

On April 26, 1995, near Red Lodge, Montana, the runaway alpha male wolf was illegally shot and killed. The perpetrator was sent to jail. The wolf’s mate and her puppies, however, were rescued and returned to Yellowstone.

Yellowstone tourists observe a herd of bison grazing in 2016. (©Getty Images | <a href="https://www.gettyimages.com.au/detail/news-photo/tourists-observe-a-herd-of-bisons-at-yellowstone-national-news-photo/532612536">MLADEN ANTONOV/AFP</a>)
Yellowstone tourists observe a herd of bison grazing in 2016. (©Getty Images | MLADEN ANTONOV/AFP)

“This couple’s blood line,” say park representatives, “can be traced in the majority of the wolf packs today.”

The gray wolf population rose steadily, and from that moment on, the park started to change in fascinating ways. These “top predators” kept the elk moving; previously overgrazed patches of land had the chance to recover and grow lush again, and an ecological phenomenon known as a “trophic cascade” began to transform the entire ecosystem.

Illustration - Pixabay | <a href="https://pixabay.com/photos/timber-wolves-wolves-family-pack-907680/">Pixel-mixer</a>
Illustration - Pixabay | Pixel-mixer
As grazing animals were kept in check, cottonwoods, aspens, and poplar trees grew, lining the rivers and stabilizing the riverbanks like never before. “Beavers came back,” Dr. Sanjayan, lead scientist of the Nature Conservancy, explained to the BBC, “and they came back on their own.” So did a huge congregation of birds and small mammals, invited back by the newly habitable landscape.

There’s little doubt that the Yellowstone gray wolf reintroduction proved that small changes can have a tremendous impact on large ecosystems.

Yet, wildlife ecologist Arthur Middleton from UC Berkeley warns us not to oversimplify. We must be careful not to “distract attention from bigger problems,” he wrote for The New York Times, or “mislead ourselves about the true challenges of managing ecosystems.”

Yet, Yellowstone National Park’s remarkable example, thanks to gray wolves, the new “forest stewards” of Yellowstone, offers a glimmer of hope for future generations and for wild ecosystems everywhere.