This winter will kill a major portion of the buffaloes in Yellowstone National Park, possibly pushing them past the point of recovery, the world’s top expert on the herds says.
“My best-case scenario is we’ll have a major population crash this winter,” said Mary Meagher, a National Park Service scientist who has studied Yellowstone bison for 38 years.
“My worst-case scenario is the system will collapse.”
Meagher said she is not predicting extinction, but herds in some parts of the park could be especially hard-hit.
Deep snow came early to the park. Then a warm spell made slush, followed by bitter cold that turned the slush to ice that the buffaloes can’t get through to graze.
They already are eating bark and pine needles.
“That’s starvation food,” Meagher said.
“I’ve seen enough already this winter to tell you there will be a population crash. I can’t tell you how far it will go.”
More than 600 of the big animals have been shot at the border or captured for slaughter this winter to protect cattle in Montana from the brucellosis that some of the buffaloes carry.
But that is not the major culprit, Meagher says.
The heart of the problem, she told the Bozeman Daily Chronicle, is the park’s interior roads, which are groomed and hard-packed to accommodate snowmobiles and snow coaches for winter tourists.
By using those trails instead of floundering through deep snow, the buffaloes save an incredible amount of energy, and many more survive the winter to give birth in the spring.
Meagher estimates the bison population reached about 4,000 in 1994-95 - about double what it would have been without winter tourism in the park.
When they reached the 4,000 level, the buffaloes began to drop in number naturally and gradually.
Now, with an especially hard winter at hand, the mortality rate could go a lot higher even if there were no killings at the border.
Winter range in the park is relatively small.
“What governs population levels is winter, and we’ve changed that whole relationship,” Meagher said.
“Winter no longer is keeping the lid on. The entire habitat all year is changed.”
Her worst-case scenario of a “collapse of the system,” which she described as “very likely,” depends on how the rest of the winter shapes up. A system collapses only after years of activities that lead up to such a collapse, she said, comparing the situation with Pacific Northwest salmon.
“It took 50 years to get there, but the salmon population has collapsed,” she said, and now nobody is sure quite what to do about it.
Without the winter roads, Meagher believes, the Yellowstone bison population would hover around 2,000. Because the roads have distorted both population levels and distribution, she said, bison could become a rarer sight in Yellowstone after this winter.
The population “may fluctuate at a much lower level,” she said. “Five hundred? A thousand? I don’t know.”