buffalo in America once numbered 30 to 60 million, ranging
from Virginia to Alaska and all points in between. Today the
only buffalo to have continuously occupied their native range
number approximately 4,000 and are being forced to live inside
the inadequate confines of Yellowstone National Park. Year
after year, during their annual migration, buffalo are repeatedly
hazed, captured, and sent to slaughter as a result of an agreement
between federal and state agencies that places the economic
interest of Montana’s livestock industry above the welfare
of the Greater Yellowstone Ecosystem.
Buffalo are migratory animals, and like other wildlife they
migrate to lower elevations every winter and spring for improved
forage. This natural migration leads them across the Park
boundary into Gallatin National Forest. In the early 1900’s,
scientists and legislators realized that Yellowstone National
Park did not reflect the natural boundaries of the ecosystem
(they forgot to include winter habitat), and therefore didn’t
meet the needs of wildlife. Hence, in 1926, Gallatin National
Forest was established to provide winter habitat. Unfortunately,
Gallatin National Forest is located within Montana’s
borders, and at the behest of Montana’s livestock industry
the state maintains a zero-tolerance policy for wild buffalo.
Strangely, given the historic population of the buffalo, it
is frequently stated that 4,000 buffalo is too many. It is
alleged that the number exceeds the ecological carrying capacity
of Yellowstone’s habitat, thereby justifying hundreds
being put to death every year.
is the carrying capacity for Yellowstone National Park relative
There is no simple carrying capacity figure for any wildlife
species, and the number is in constant flux. The truth is,
we need to think outside the box; Yellowstone National Park
is drawn like a box, and it neither reflects the ecosystem
nor the needs of the creatures that are part of that ecosystem.
The tremendous influence natural variations have on sustainable
population levels must be taken into account when contemplating
carrying capacity. Weather patterns such as wet seasons, times
of drought, harsh winters or milder winters impact populations.
Predator-prey relationships also alter the picture. Carrying
capacity is wrongly being considered only for the Park, within
a political boundary invisible to wildlife, rather than being
extended to adjacent public lands (i.e. Gallatin National
Forest) from which buffalo are systematically excluded.
A figure of 3,000 buffalo, cited in the Interagency Bison
Management Plan, is frequently touted as a carrying capacity.
It is not. Rather than being based on available habitat or
sound science, this figure is politically derived.
A National Academy of Sciences study conducted in 1998 determined
that “even at 3,500 bison, little or no evidence exists
to indicate that forage quantity or quality is inadequate.”
The report goes on to say that even if the buffalo population
has enough forage to maintain itself above 3,000 animals,
natural weather factors that prevent buffalo from accessing
that forage, such as deep snow, will cause them to migrate
to lower elevations, and out of the Park.
The 3,000 buffalo constraint is simply being used to make
it more convenient for buffalo to be managed, at the expense
of the wild nature and genetic integrity of America’s
last wild and unfenced herd. Further, the Park Service has
a clear statutory mandate for noninterventionist wildlife
management. In other words, natural factors are intended to
regulate the size, distribution, movement patterns, and habitat
use patterns of wildlife within our parks.
What we do know for certain is that, due to yearly killing
3,725 buffalo have been slaughtered in the past fifteen years.
We haven’t allowed natural forces relative to buffalo
to take hold in and around Yellowstone. When buffalo leave
the Park and enter Montana, Department of Livestock officials
take charge. Instead of wildlife biologists, brand inspectors
control wild buffalo, and biologists don’t have a chance
to evaluate natural population possibilities.
The overpopulation argument is made for buffalo, elk, and
other ungulates. The park is said to be overgrazed, yet for
at least the past century, there’s arguably been no
better place in the United States to witness wildlife than
Yellowstone. It is now, and for decades has been, America’s
wildlife Serengeti. The notion that the Park is overpopulated
and the buffalo population unsustainable is simply not true.
Montana has a grand opportunity that would be the envy of
the entire country; Instead of driving a policy to kill America’s
last wild buffalo for reasons that have little to do with
disease or population control, Montana could be the only state
to boast a truly wild, free-roaming herd of buffalo. Buffalo
are the icon of the West, and Montana should consider celebrating
them as its national mammal. Montana can end the buffalo slaughter
that began in the 19th century once and for all. Montana has
the wisdom and national support to make it happen.
Aspects of Bison Density Dependence in Yellowstone National
Park- October 2000 This paper capitalizes on a unique
opportunity provided by the record of the bison population
of Yellowstone National Park (YNP). This population has been
intensely monitored for almost four decades. There does not
appear to be another comparable data set in existence for
a very large highly gregarious herbivore (G. Caughley pers.
comm. to MM). This population has a long historical record
with some information dating back to 1860 (Meagher 1970, 1973).
Further, the YNP bison herds have been the subject of long-term
detailed and continuous ecological study since 1963. (PDF-
133 pages, 2.6MB)