Not quite 20 years ago the experiment to recover wolves in Yellowstone National Park got under way with a relative handful of Canadian wolves brought into the park. Today that genetic feedstock has produced what biologists had hoped for: a more natural wild kingdom, one with checks and balances on itself.

"In 2003, we had 174 wolves, now we have 88. Our policy is to preseve and protect, so what we’re shooting for is what I’d called a natural density," says Doug Smith, a wildlife biologist who oversees the park's Wolf Project. “We’re at that now."

Mollies Pack, the park's biggest, roams Yellowstone's interior. NPS photo from December 2011.

According to the park's annual report on the wolf population, coming into 2012 at least 98 wolves in 10 packs and two loners roamed Yellowstone.

"The number of breeding pairs (8) was the same as in 2010, when the population size was 97. However, the northern range wolf population has declined approximately 60 percent since 2007, mostly because of a smaller elk population, the main food of northern range wolves," the report's Executive Summary notes. "The interior wolf population has declined less, probably because they augment their diet with bison."

Of course, since the start of 2012 the wolf population has dropped some more, most recently due to the deaths of seven wolves with ties to the park that found themselves in the gunsights of hunters. Dr. Smith doesn't believe the loss of those wolves has jeopardized the long-term viability of Yellowstone's wolf population.

While some of the shot wolves might have been alpha males or females, alpha animals have been killed by rival packs inside the park in the past, he pointed out. Some years back the alpha female of the Nez Perce Pack was killed by another pack, he said, and while "the four remaining wolves went every which way," the void created by the pack's demise was filled by the Gibbon Pack.

"Does it (hunting) affect the population biologically? Probably not," said Dr. Smith. "But does it affect the research? Yes. Right now we're trying to track a pack out there, and they have no collars."

Among the wolves recently shot was a male whose home range normally revolved around the Pelican Valley. Fall, though, is perhaps the toughest time of year for wolves that rely on bison and elk for their meals, as the lack of snow allows the prey to be more nimble in avoiding the predator.

"My chin dropped when I heard 824 got shot, because he lives in the middle of the park, and he got shot along the north boundary," said the wildlife biologist. "You're going to get that kind of movement in the hunting season because it's a hard time to be a wolf."

Dave Hallac, chief of Yellowstone's Center for Resources, agreed that hunting might cost the park some of its alpha wolves, but downplayed the overall impact that would have on the park's packs.

"Sometimes the packs will dissolve, and that also happens naturally," he said. "Wolves kill other wolves, and alpha males will come in and kill other alpha males. These things happen naturally. The real question is, from a bigger scale view, what are the impacts of that to the Yellowstone population?

"Does it mean an end to wolves in the park? No."

Declining along with the wolf population in recent years has been Yellowstone's elk population. While there was a big outcry by some hunters in January 2011 when the park's annual elk count tallied just 4,635 elk, a 24 percent decline from the 6,070 animals counted a year earlier, today Dr. Smith believes that elk population is more in line with historic numbers.

"I think our elk population now is more like it was in 1872 than it was 20 years ago," he said. "Our business is not to raise elk. Our business is to restore natural systems.'

Back in 1995, when Yellowstone's wolf recovery program began, the northern elk population count was 16,791 animals, and not too many years before that it had even approached 20,000.

Today's equilibrium in Yellowstone's wild kingdom goes beyond wolves and elk, said Dr. Smith. Wolves, bears, cougars all are "at a 100-year-high" in numbers, he said.

"We wiped out wolves, we wiped out cougars, we reduced bear numbers," the wildlife biologist added. Now, with wolves and cougars back in the park and bear numbers rising, the overall result is a healthier ecosystem, he said.

"I think that's very much in line with the objectives of the National Park Service. And that means fewer elk. For the National Park Service, that's good. For a guy (hunter) who lives right next door to the park, that's bad."

But the health of the park's ecosystem is good for Yellowstone's visitors, and for the surrounding communities that benefit from their spending. During 2011 an estimated 25,000 Yellowstone visitors saw wolves. It has been estimated that the park and its gateway communities see more than $35 million a year in revenues related to wolf-watching.