Around Yellowstone National Park, five wolf dens are alive with new litters, leading biologists to predict that the wolf packs introduced into the park from Canada during the past year and a half will thrive on their own without more imports.
"Wolf reintroduction is done, unless something unusual happens," said Ed Bangs, a biologist with the Federal Fish and Wildlife Service who helped to coordinate the airlifts of gray wolves from Canada over the past two winters.When Yellowstone opened fully on May 15, wildlife watchers found that the population of wolves had tripled from that of last year. In addition to 17 adult wolves that were added in January, biologists have counted eight new pups in two litters and are confident that three more females gave birth in late April.
"There are 15 to 30 new pups on the ground, making a total of 50 to 65 wolves," said Mike Phillips, head of the National Park Service's wolf restoration project.
The wolves now in Yellowstone are the first to roam the park since the 1920s, when the last of that era's population were killed off by a government eradication program favoring livestock. Three-quarters of a century later, the species has been brought back to Yellowstone, and to locations in Idaho and western Montana, by the federal restoration project, which sprang largely from an overpopulation of elk.
In their new habitat, the wolf packs of Yellowstone have proved to be voracious eaters, killing an elk about every five days as well as an occasional mountain sheep, mule deer or moose.
The consolidation of the park's new wolf packs has defied not only court challenge and hostile politicians but also misadventure. Of late, gunfire or nature has killed at least one adult wolf a month. In February, one was killed by a mountain lion in western Montana, and another, which had wandered 80 miles south of the park, was shot by a passer-by. In March, a rancher shot a wolf that was roaming through a calving pasture 50 miles west of the park. And on April 14, an adult female fell into a Yellowstone thermal pool and was scalded to death. A necropsy showed that she had been just two weeks short of delivering six pups.
For all that, Bangs said, the program is doing well. "Over all," he said, "we expected a 30 percent mortality rate. Instead, we have a 15 percent mortality rate."
It is the wolves' propensity to foray beyond their Yellowstone base that makes the park's neighbors nervous. Two packs have established dens in Montana at sites about 35 miles northeast of the park. In April, one wolf roamed even farther north, to the town of Reedpoint, only 50 miles west of here. Already a federal judge in Wyoming is considering four lawsuits, backed largely by ranching groups, to reverse the wolf restoration program.
And, in an election year, some Western politicians are now accusing one another of being "soft on wolves."
Sen. Max Baucus, D-Mont., recently traveled to the heart of his state's cattle country and denounced the multimillion-dollar program for "Cadillac expenditures." In retort, his Republican challenger, Dennis Rehberg, cited a "dramatic election-year conversion." Noting the senator's earlier support for wolf reintroduction, Rehberg accused him of having joined forces with Washington politicians "that don't give a hoot about Montana ranchers and farmers."