At Yellowstone, a not-so-simple life

YELLOWSTONE NATIONAL PARK — The summer traffic jams in Yellowstone, the nation's premier national park, are worst when a grizzly bear is foraging for berries in an open ditch or a herd of bison is crossing the road. Brake lights go on, and families huddle outside their cars in awe.

But a glance at these majestic animals does not reveal the complexity of the ecosystem in the park. Nor does it reveal the escalating conflict involving the animals of Yellowstone and their human visitors and neighbors.

Grizzly bears, for example, were removed this spring from the endangered-species list after their numbers in the park began to soar. But the bears have begun to wander outside Yellowstone, rifling through trash cans and occasionally attacking residents, prompting state officials in Wyoming, Montana and Idaho to consider allowing trophy grizzly-bear hunting for the first time in three decades.

Yellowstone cutthroat trout, native to the region, are at their lowest population in centuries after non-native trout entered park rivers. The new trout killed millions of cutthroat trout, in turn causing the park's populations of species that feed on the fish — such as ospreys — to decline at "staggering" rates, according to the park's top bird expert.

Bison, a symbol of the American West, are flourishing in the park but increasingly roaming far beyond it. A recent outbreak of a bacterial disease common in bison has cattle ranchers fearful the bison could contaminate their herds.

Perhaps most contentious of all, gray wolves, once virtually extinct in the West, were reintroduced to the park — and thus the region — in the mid-1990s. They are thriving and on the verge of removal from the endangered list, but the potential delisting has ignited a bitter debate between beef ranchers and conservationists about how to simultaneously protect livestock and continue to let the wolf population expand.

"Holistic approach"

"You have to take a holistic approach to conservation when it comes to Yellowstone," said Craig Kenworthy, conservation director for the Greater Yellowstone Coalition. "Because literally everything is interrelated."

If nature is a circle, nowhere is it more apparent than places like Yellowstone this summer. For the first time in decades, aspen and willow trees are making a comeback in a park long dominated by pines.

Many biologists attribute it to the gray wolf, because elk — one of the wolf's favorite prey — are increasingly reluctant to venture into open spaces to munch on the tasty tree shoots. As the new trees grow, so too have songbird populations.

"The gray wolves are doing very, very well," said Doug Smith, head of Yellowstone's wolf-reintroduction program.

The gray wolf is getting a less enthusiastic reception from two groups. Hunting outfitters in the states Yellowstone touches — Wyoming, Montana and Idaho — said wolves are wiping out elk, the trophy game high-paying clients most want to shoot. Ranchers said livestock kills from wolves are soaring and the costs of protecting their herds are becoming untenable.

"You used to have to ride herds once every couple weeks to check in on them," said Jay Bodner, natural-resources director for the Montana Stockgrowers Association. "But since the wolf population has increased so dramatically, you're seeing folks have to hire people to ride almost every day in an effort to protect their herd."

Once delisting occurs, states, rather than the federal government, will be charged with managing their wolf populations. That has led to debates about how wolf-hunting seasons might be handled, whether ranchers would be allowed to shoot wolves out of season to protect cattle and whether there should be federal compensation to ranchers who lose stock to the wolves.

Critter jitters

Many residents in the region fear some animals' comeback may bring danger to their backyards. Because of the protection offered by the park, the grizzly population has soared from 200 bears to more than 600 in recent decades, even as their source of food — Yellowstone cutthroat trout — has plummeted. It is expected the grizzlies will begin roaming outside the park to hunt for trout, and human-versus-bear conflicts are likely to follow. This spring, a man was mauled in the park by a grizzly; though he survived, game officials killed the animal.

Few local governments around Yellowstone have laws that address the bears, but a few are starting to attack the bear problem. For example, some municipalities mandate bear-proof garbage cans and bins, and outlaw planting fruit trees or stocking ponds with fish, both of which would attract bears.

The bison synonymous with Yellowstone have become the latest source of contention. Yellowstone is in the midst of a 10-year drought while its bison population is at one of its highest levels. With not enough grass for grazing, the bison are wandering outside the park, grazing on cattle ranchers' property and potentially exposing livestock to brucellosis, a disease that causes pregnant cows to abort.

Bodner, of the stockgrowers group, said the bison herds at Yellowstone have grown too large; he thinks this year's count will reach nearly 5,000. He proposed that hundreds, or more, be killed or moved from the park. "Listen, I appreciate that park, too," he said. "But we have to find a way for the park and the rest of the region to coexist."