In response to a guest editorial I published in the Missoulian on the shameful slaughter of Yellowstone’s bison, a group of three retired USDA range managers wrote a commentary that was published in the Missoulian on December 30th on Yellowstone’s bison. They argue that bison numbers must be reduced, and thus implicitly supporting the Dept. of Livestock’s agenda for controlling park bison. Though I have no doubt that their motives are to protect the park’s resources, the issue is more complex than they suggest.

Here is a link to their commentary. http://missoulian.com/news/opinion/columnists/reducing-bison-population-key-to-saving-yellowstone-s-northern-range/article_89d6b7ad-9f19-5ccf-bce1-b544adc0bf14.html

The idea that Yellowstone is “overgrazed” is an old debate that has been on-going for decades. Without getting into the weeds too much, I try to provide some perspective in my comments below.

The bottom line is that bison are bottled up in Yellowstone due to livestock policies that interferes with natural migration. Until bison can move freely on to other public lands, it is disingenuous to argue that we need to reduce bison numbers.

The debate about native wildlife grazing influences, particularly elk, has been argued for decades, particularly by those trained in livestock management, as is the case with the authors of this commentary.

The traditional range management approach ignores many unique factors about wild ecosystems and does not transfer readily to Yellowstone’s wild ungulates.

D omestic livestock are concentrated on public lands in the summer months when plants are actively growing. The negative consequences of livestock grazing are well documented which includes reduction in seed production, loss of vigor, and selective removal of perennial plants.

Damage to riparian areas by bank breakage and soil compaction, social displacement of native ungulates like elk as well as the forage competition with native wildlife from butterflies to elk are also other livestock induced impacts.

By contrast, overall wildlife numbers are much lower than domestic livestock and are widely distributed during the summer, reducing ecological impacts.

For decades, I have hiked weeks at a time in Yellowstone’s backcountry leading trips as a commercial guide, as well as for my own enjoyment. Even during the 1980s and 1990s when many asserted there were “too many” elk in Yellowstone, I could go days and sometimes a week or more in the backcountry without seeing more than a few elk at a time and an occasional small herd.

Elk, bison and other native ungulates are only concentrated at lower elevations in the winter months when plants are dormant. In addition, soils are frozen, so compaction, and bank breakage all of which helps to reduce the browsing/grazing impacts associated with native wildlife.

Though Park willow and aspen were often hedged (short), they persisted despite heavy browsing pressure because they could put out leaves in the summer months and grow without significant browse pressure, maintaining seed and energy production. Interpreting bison and elk influences without considering seasonality of use is a mistake.

Furthermore, there is another temporal aspect to the entire debate of wildlife numbers as well. Wildlife populations fluctuate over decades in response to long term climatic conditions, predators and other influences. Just as wildfire comes and goes over decades in the Yellowstone ecosystem, so does the grazing/browsing effects of native wildlife.

By contrast livestock are shielded from these kinds of stresses. If the winter is harsh, they are fed supplemental feed. If there is drought, they are brought water. If there are predators–well we know what the livestock industry does about them. In short, livestock are sheltered from significant population fluctuations, while wild ungulates are not.

As we have seen with regards to Yellowstone’s elk herd, the presence of wolves, combined with other factors like changing migration patterns, drought, harsh winters, and wildfires has led to an overall reduction in elk influence on plant communities.

Evolutionarily plant communities are adapted to periodic heavy use-which is why many shrubs and trees sprout from roots and can persist for decades with heavy WINTER browsing. However, plants also get periodic relief from heavy ungulate browsing due to natural ungulate population fluctuations.

The authors also assert that research by Charles Kay and others demonstrated that elk and other ungulates were rare in the mountains

Yet nearly all early references to wildlife in the park region by trappers, miners, and military expeditions cited by Kay, were recorded in the SUMMER months when wildlife is widely distributed. Even on the Great Plains, wildlife was patchy in distribution, and expeditions could go weeks and months without seeing a single bison herd.

When the Lewis and Clark expedition traveled up the Missouri River in Montana in 1804, they noted an abundance of bison. Yet, on their return trek, the Corps of Discovery split at Lolo, Montana. William Clark traveled hundreds of miles in bison habitat including down the Upper Missouri tributaries to Three Forks, through the Gallatin Valley where Bozeman is located, over Trail Creek by Livingston, and down the Yellowstone River nearly to present day Billings area before he encountered a bison herd.

I can provide many other similar references that recorded both an abundance, as well as absence of bison on the plains. One must be careful to account for season of observation, as well as local climatic conditions, predators, and other factors that influenced wildlife numbers and distribution.

Bison remains have been recorded in many mountain locations, including at elevations of over 10,000 feet in Colorado and elsewhere. With freedom to migrate, ungulates in mountain locations generally wintered at lower elevations.

The major problem Yellowstone’s bison is that the traditional migration routes are blocked by hunters and Dept. of Livestock agents who corral bison for slaughter.

If there are too many bison for the northern range, it is an entirely artificial problem created by the livestock industry. Until we free up bison to move to other public lands outside of the Park, one cannot assert that reductions are necessary.