Many researchers in western national parks have not been taking into account the historic impact of gray wolves, according to a new report.
Before the 1930s, gray wolves were some of the most widespread large carnivores in the American West, said one of the study’s authors, Oregon State University Professor of Ecology William Ripple.
“So, they were ubiquitous before humans eradicated them from many areas,” Ripple added.
He said this resulted in big spikes in elk and deer populations, which have overgrazed and damaged plant populations, affecting the biodiversity of the ecosystem.
In Yellowstone, researchers found that once wolves were removed from winter ranges, the elk population grew, resulting in erosion, and depleted aspen and willow trees.
But Ripple said 60% of the ecological studies he examined failed to mention the historic presence of gray wolves.
“It's the environmental equivalent to diagnosing a sick patient without having a baseline health exam,” he said.
Ripple said some ecosystems — like Yellowstone’s — are starting to come back with the reintroduction of wolves. Having the apex predator in the park has kept elk on the move. In the past, elk feasted on aspen and willow spouts, so these trees have now recovered from intense grazing.
Still, Ripple said researchers and policymakers across the West should still recognize how humans changed the landscape by removing the species decades ago.
This comes as many western states are seeing fiery debates about how best to reintroduce and manage the species.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio (KNPR) in Las Vegas, Boise State Public Radio in Idaho, KUNR in Nevada, KUNC in Colorado and KANW in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.
