Anna Hebblewhite got an unexpected science lesson on her first big hike with dad.
University of Montana wildlife biologist Mark Hebblewhite and his 3-year-old daughter were almost to Camas Lake when smoke from the Roaring Lion fire plumed over the canyon wall. The next thing they saw were bands of elk, heading south away from the blaze.
“It was her first backpack trip – I coerced her with M&Ms and fishing,” Mark said. “We had just got to the lake and turned around to see the fire blow up. So we turned around and booked out. I know the fire was a tragedy for the people affected by it – a tragedy for those whose houses burned. But for the wildlife, it’s not actually a disaster.”
When he saw the elk moving away in the thick forest, Hebblewhite thought immediately of the famous “Elk Bath” photo taken by John McColgan as a wildfire rampaged across the East Fork of the Bitterroot River in 2000. Many assumed 16 years ago that a popular hunting area had been ruined. Two years ago, Hebblewhite and Montana Fish, Wildlife and Parks biologist Kelly Proffitt decided to check.
What they found was a remarkable rebound for the elk of the East Fork. Compared to their brethren on the less-burned western side of the Bitterroot Valley, East Fork elk had better body fat, more pregnancies and higher calf survival going into the winter months. The study found they got a wider variety of summer range vegetation to feed on in the burned areas, compared to the summer range in the West Fork.
“The main difference between the forks was the amount of areas that had been burned by fire,” Hebblewhite said. “The East Fork went from old, decrepit, overgrown forest to an increased amount of grasses and flowers like lupine and balsamroot. And we could track that through the body condition of female elk.”
The East Fork area has a lot more winter range for elk than the West Fork does, in the ranches and farms around Sula. But the high-elevation summer range is similar in both drainages, so that’s why the biologists concentrated on the nutritional value of summer forage. And that’s the area that burned, both in the past fires and this summer’s Roaring Lion inferno.
Elk grazing in those burned-over areas had an 89 percent annual pregnancy rate, compared to 72 percent for elk in unburned summer range. They went into winter with 7 percent to 8 percent body fat, while West-side elk had significantly lower levels.
Roaring Lion may not produce noticeable bumps in elk populations, according to Montana Fish, Wildlife and Parks Region 2 Research Technician Ben Jimenez. But it won’t hurt, either.
“That’s not been a real productive area, summer-range-wise,” Jimenez said.
The canyon walls tend to be too steep for grassy meadows to establish until things level out at the upper end of the drainages. But for the elk that do make a home there, stimulating lots of new grass and bush growth will be appreciated.
In comparison, wildfires in 2010 and 2011 farther south along the West Fork of the Bitterroot River are expected to produce a good bump in summer range productivity, Jimenez said. That area will be carefully watched to see if elk numbers follow the same rise seen in the East Fork.
The scientific journal Ecological Applications posted the article online in May and will release a printed version later this year. Its co-authors were Wibke Peters, Nicole Hupp and Julee Shamhart.