Ecological changes linked to wolves
By Warren Cornwall
Seattle Times staff reporter
Ten years ago today, the first of eight travel-weary wolves stepped out of its cage and into Yellowstone National Park.
Those steps — the first known wolf prints in Yellowstone in decades — created ecological and social currents that are changing the landscape in parts of Montana, Idaho and Wyoming.
The return of one of the region's top predators, now numbering up to 900, may be altering everything from elk behavior to tree growth to beaver populations. Ranchers manage their livestock differently, and some face wrenching losses. Hunters now pursue wolf-spooked elk.
The changes offer a glimpse of what the future may hold for parts of Washington, where it's only a matter of time before wolves take up residence, biologists say.
Oregon State University forester Bill Ripple went to Yellowstone National Park in 1997 looking for an answer to the decline in aspen groves there. He emerged with a surprising answer: wolves.
A study of growth rings on the trees showed that the youngest dated to the 1920s, around the time when wolves were eradicated from the park. Ripple hypothesized that the disappearance of the predators emboldened elk, which then ate young, tasty trees with impunity.
AP
A wolf walks through the snow in Yellowstone National Park in Wyoming, where the animals were reintroduced a decade ago. Today, 850 to 900 of the animals roam parts of Montana, Idaho and Wyoming.
He and a colleague followed up with research that found similar age patterns in cottonwood trees, and evidence that willows have had a resurgence in recent years.
"As soon as we get rid of wolves, plants stop flourishing. Soon after we bring wolves back, plants are flourishing again," Ripple said.
If true, it shows how wolves can influence a broad web of plants and animals. Beaver rely on willows for food and songbirds live in aspens and willows, so their populations might rebound. Animals that thrive around beaver dams could get a boost. Already, a part of the park now hosts nine beaver colonies where there was one when the wolves first arrived, said Douglas Smith, the lead wolf researcher at Yellowstone National Park.
The wolf's arrival also has coincided with a 50 percent drop in coyote populations, Smith said. That could help red foxes, which are killed by coyotes. It also could increase populations of rodents eaten by coyotes, a potential boon for hawks that prey on mice.
"We've grown accustomed to what the world looks like without top-level carnivores. Here you've got a place where they're all present, and it looks real different," he said.
Not all scientists are persuaded of the wolf's transformative effect. Duncan Patten, a Montana State University ecologist, said it's hard to separate the wolves from other factors, such as drought and mild winters in recent years. Willows, for example, may be rebounding because there hasn't been a harsh winter forcing elk to dine on the woody brush, he said.
"There are a lot of things going on," Patten said. "The unfortunate thing is too many people do what I call single-factor ecology and point at the wolves as the only factor."
The fate of elk is also in dispute. The park's biggest herd has fallen from 20,000 to 10,000 since the wolf's return. Smith said wolves are just one factor, along with hunting, grizzly bears and drought.
But the decline has been controversial, as hunters confront a dwindling herd and state officials point to the wolves.
Kurt Alt, a Montana state wildlife manager, said he thinks the wolves are playing a critical role. Still, elk aren't declining in other parts of Montana where wolves aren't as concentrated, Alt said.
Margaret Soulen Hinson doesn't doubt that wolves were responsible for the loss of as many as 300 sheep on her central Idaho ranch last summer.
She, her family and shepherds tried everything from using guard dogs to sleeping overnight on the ground with her sheep to ward off the predators. Eventually, government agents resorted to killing 12 wolves to try to stop the carnage.
"I'll be honest, I think we can live with some wolves. But certainly this past summer was too much in loss and very difficult for everyone. We simply couldn't figure out a way to keep the wolves out of the sheep," she said.
The wolves' quick spread has been a surprise to some. In 1995, the only known packs in the western United States lived in the remote northwestern corner of Montana. The animals were listed under the Endangered Species Act.
That year, in a move that drew furious opposition from ranchers and state officials in Idaho, Montana and Wyoming, the federal government began releasing Canadian wolves in Yellowstone and central Idaho, eventually introducing 66 animals.
"When we put those wolves in, we thought it would take a few years before we had reproduction, and they proved us wrong because we had pups that first year," said Joe Fontaine, assistant recovery coordinator for the U.S. Fish and Wildlife Service, which has overseen wolf reintroduction.
Today, between 850 and 900 roam parts of those three states, Fontaine said. The wolf soon could be dropped from the Endangered Species list, if an agreement is reached with Wyoming over how the state would manage the animals. Environmentalists are guardedly optimistic about the future of wolves in those three states. But they have sued the federal government to keep federal protection for wolves that venture into other states, including Washington.
How this will play out in Washington depends partly on what the wolves do, and whether they thrive in a more populous state with fewer stretches of uninterrupted wilderness.
Wolves once lived across much of Washington but had been largely eradicated by the 1930s. A lone radio-collared wolf coming from Montana passed through the state's northeastern corner in 2002, before continuing to Canada.
Washington wildlife officials point to the eastern edge of the state, around the Selkirk Mountains to the north or the Blue Mountains to the south, as likely places for wolf packs to become established. The Cascade Mountains are another potential spot.
Jere Dennis, a rancher in northeastern Pend Oreille County, is convinced he's already living with wolves. Twice he's seen what he says was a wolf near where he grazes cattle.
"If they don't increase any more from what they are right now, I think we can live with it. If they get to bringing them in and the numbers increase, sure, we're going to have problems with them," he said.
Washington state officials are preparing for their eventual arrival by meeting with federal officials to craft rules governing what to do if a wolf is spotted or starts preying on livestock.
But they haven't started the often contentious process of creating a statewide plan for how to manage them — a process that could trigger many of the same debates that preceded those first wolves in Yellowstone a decade ago.
Warren Cornwall: 206-464-2311 or wcornwall@seattletimes.com
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