Return of the Big Predators

As wolves spread across the American West and even into areas of the East Coast, where their official presence has yet to be acknowledged, Ph.D. student Cristina Eisenberg’s findings about their place in the ecosystem could help policymakers answer questions about the best way to manage them.  

It’s a timely issue, as their reemergence is predictably eliciting extreme reactions from people. This polarization, as well as Eisenberg’s science, has received a good amount of press lately. Eisenberg’s work has been featured in the March 2010 issue of National Geographic, and the Feb. 15, 2010 issue of High Country news, to name just two.

Eisenberg sees her role in “the wolf problem” as an informer to policymakers. Her data, she hopes, will create common ground in places where conversations between those who love wolves – and those who don’t – are usually considered implausible.

A Family History

It may be that Cristina Eisenberg picked up a reverence for wolves from her father. Growing up on a ranch in northern Mexico, he was assigned the job of killing any wolf he saw.  But he couldn’t bring himself to shoot the animals. Instead, he’d watch them as they trotted through the cattle herds he was minding. Always the wolves left the cattle unharmed – they were on their way, perhaps, to more appealing prey. 

So when Eisenberg told her father she was planning to study wolves, he was pleased. “I’m so glad,” he told her. “There’s so much we don’t understand about these animals.”

Eisenberg’s desire to understand wolves unfolded when she and her husband moved from coastal California to northwestern Montana with their two young daughters in the mid-90s. The presence of wolves there was unmistakable, from their howls on the mountain outside Eisenberg’s cabin to their tracks in the snow by her door. When one bolted through her yard in pursuit of a deer when she and her daughters were gardening, she became irrevocably curious.

Her children also asked her questions she couldn’t answer – about trees, plants and the other animals that appeared on her land, which is situated alongside one of the biggest wilderness areas in the lower 48. Her children’s questions, as much as the bolting wolf, catalyzed her transformation from artist and housewife to scientist.

“I saw everything change on my land when wolves returned to that ecosystem. So those connections – the ones Aldo Leopold wrote about so eloquently in his Sand County Almanac and other writings – inspired my master’s degree, which was policy-based. After I became familiar with the policy, I really wanted to understand the ecology of it,” she says.

Studying Wolves

That curiosity led her to Oregon State in 2006 to begin Ph.D. research with forestry professor Bill Ripple. For the past four years, Eisenberg has used a mix of forestry and wildlife biology methods to study the effects of wolves on ecosystems in Montana’s Glacier National Park and Alberta’s Waterton Lakes National Park. Specifically, Eisenberg has looked how wolves’ presence effect elk populations in the park, and in turn aspens and aspen-dependent species like beavers and songbirds.

Her findings, like Ripple’s and Oregon State professor Robert Beschta’s, indicate that wolves have powerful effects on ecosystems—from the songbirds to how the shrubs and trees grow, but that these effects may be related to wolf density and distribution. Her findings, which will be published later this year, suggest that wolves are a complicated and sometimes sticky species to manage.  “You can’t manage a wolf just like it was an elk or any other game animal, because the effects they have on ecosystems can be so complex and profound. You have to look at them in a different way,” says Eisenberg. And that, she says, changes the way people look at their resources.

Because she comes from a ranching background, Eisenberg’s attitude on wolves is pragmatic. “It’s not what people always expect me to say, but I don’t think wolves belong everywhere, and I do think they can be challenging to live with,” Eisenberg says. “I also think they’re fascinating creatures. And they are incredibly intelligent.”

Eisenberg’s pragmatic views on wolf conservation have earned her funding from unexpected places, like the hunter-conservationist club Boone and Crockett, and Shell Oil.

The Future

After she finishes her Ph.D. this spring, Eisenberg will be taking a post-doc position at Oregon State with professor Norm Johnson. She is in the process of publishing a book with Island Press based on her Master’s research, “The Wolf’s Tooth: Keystone Predators, Trophic Cascades and Biodiversity.” She will also be working on a five-year project on how top predators affect a mixed-use landscape at High Lonesome Ranch in northwestern Colorado. Usually, Eisenberg says, apex predator studies take place in relatively contained environments, like national parks. But the landscape surrounding High Lonesome is subject to ranching, hunting and oil and gas development. And wolves have begun moving into that territory.

Eisenberg wants to see how the systems change when their numbers grow. What she finds could have bearing in a place like Oregon, where wolves are showing up on forest service as well as privately owned lands. “I want to understand the ecological implications of wolves in a landscape where timber harvesting and ranching are happening,” she says.

Ultimately, Eisenberg’s goal is to answer questions about how wolves affect ecosystems. She credits Oregon State University with providing her an outstanding environment of academic freedom and support to do work that at times is seen as controversial.