George Wuerthner’s recent (Dec. 20) guest column “Save Yellowstone bison from slaughter,” complaining about population control of Yellowstone National Park bison, fails to recognize one of the most significant conservation issues in the West – overgrazing of Yellowstone’s magnificent Northern Range. Severe, prolonged overgrazing of the Northern Range in Yellowstone National Park by elk since the 1920s and now by bison has, and is still, significantly degrading the land. Bison conservation and recovery of free-ranging populations are very important, but no single species' needs outweigh the obligation to protect the land (soil-water-vegetation), the basic units of conservation for all life on our planet.
Aldo Leopold, widely recognized as the father of modern game management and outspoken advocate for both wilderness and sustainable working lands management, said, “I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer. And perhaps with better cause, for while a buck pulled down by wolves can be replaced in two or three years, a range pulled down by too many deer may fail of replacement in as many decades.” The Northern Range of Yellowstone National Park is far beyond the potential for recovery in two or three decades.
Yellowstone National Park biologist George Wright reported that the condition of the Northern Range was “deplorable” in the 1920s. Conditions are far worse now. A 1963 ecological condition inventory of the Northern Range showed a strong downward trend even though at that time there were still significant areas of “good to excellent” range condition. We volunteered to follow up on that inventory and other sources of information documenting the condition of the Northern Range in response to a request from a longtime ranching family who neighbors Yellowstone National Park to: “save Yellowstone National Park for my kids.” That was four years ago. Our follow-up shows that there is no “good” or “excellent” condition range left. But, there is dramatic loss of topsoil, invasion by exotic, noxious weeds and loss of native vegetation, including grizzly bear food plants.
In the late 1960s, Aldo Leopold’s son, A. Starker Leopold, advocated for Yellowstone National Park to represent a “vignette of primitive America” – and strongly urged Yellowstone National Park management to continue control of a burgeoning elk population. But public outcry against culling elk caused the National Park Service to invent their natural regulation hypothesis, which has pushed the Northern Range ecosystem beyond the ability to recover in any reasonable time period. Clearly, the hypothesis has not been supported by what is happening on the land.
Dave Rosgen, internationally known stream restoration ecologist, told Yellowstone National Park management over 25 years ago that streambank erosion in the Lamar Valley was over three orders of magnitude (30 times) greater than in his high functioning reference area. Once again, conditions are far worse now. Utah State University ecologist Charles Kay determined that over 90 percent of historic aspen and tall willow communities have disappeared on the Northern Range. That represents a dramatic loss of biodiversity in the name of creating a large ungulate zoo for the public to mistakenly regard as “natural” for Yellowstone National Park.
Charles Kay and former Yellowstone National Park ecologist Richard Keigley have shown that bison and elk were not common in Yellowstone national Park historically because of the combined effect of deep winter snow, high elevation, predation and the fact that these ungulates were primarily plains animals. The Yellowstone National Park ecosystem is not adapted for large populations of elk and bison.
There are at least 10 times too many bison on Yellowstone National Park’s Northern Range. It is essential for the health of hundreds of thousands of acres of our first national park to find a way to drastically reduce the bison herd through a combination of hunting and moving animals onto the plains – in a way that doesn’t simply move the overgrazing to yet another ecosystem.
And that brings up one final point: Who is George Wuerthner to tell American Indian people that they shouldn’t exercise their tribal treaty rights to hunt bison in the Yellowstone ecosystem? Exercising their treaty rights is a partial solution to the continued deterioration of the Northern Range resource.