YELLOWSTONE NATIONAL PARK – On Jan. 12, 1995, at approximately 8:30 a.m., the first gray wolf to set foot in
Yellowstone in more than 60 years stepped through the gate of a shipping container and into the cold mountain air
atop Crystal Bench.
Norm Bishop, 77, of Bozeman – then a Yellowstone National Park ranger and principal interpreter for wolves and their recovery – carried the second container housing the alpha male that day. In the presence of U.S. Secretary of the Interior Bruce Babbitt, U.S. Fish and Wildlife Service Director Mollie Beattie and Yellowstone National Park Superintendent Michael Finley, the wolf was released into the Crystal Bench acclimation pen where it would remain for 10 weeks before being released into the wild.
“It was a feeling of exultation,” Bishop said of that moment while driving through Lamar Valley during the predawn hours last Thursday. “These were the first wolves that had set foot in Yellowstone since maybe the 1930s. It was an impressive moment, certainly for me.”
Now, some 15 years on from that cold January morning, Yellowstone’s wolf population has flourished with estimated numbers today hovering around 100 wolves in the park. The reintroduction of wolves ushered in a new era of wildlife management, not only within Yellowstone, but also in the neighboring states of Wyoming, Idaho and Montana where wolf numbers have risen above 1,000 in recent years.
With the reintroduction and subsequent delisting of the gray wolf from the Endangered Species List has come ongoing debate about the value of wolves in the Greater Yellowstone Ecosystem and the importance of a species that was hunted, poisoned and trapped to extinction within park boundaries during the 1920s.
Fervent opposition to wolves remains from livestock and hunting groups, while wildlife and conservation organizations have heralded the wolf ’s return as a touchstone moment in Yellowstone’s history. While 15 years is a relative blip on the evolutionary radar of the Greater Yellowstone Ecosystem, evidence of change in the park is becoming increasingly apparent, perhaps answering the question: What good are wolves?
“Wolves are a keystone species,” Bishop said. “That is to say that they have impacts on the system beyond what you might expect based on their numbers within that system.”
That impact has become remarkably and controversially apparent in the reduction and redistribution of elk populations within and around Yellowstone. Back in the 1870s, Yellowstone National Park was being market hunted for wolves, fox, coyote and other wildlife. Market hunters would place strychnine on the carcasses of animals they had killed and skinned, returning the following day to retrieve the animals the poison had killed. Wolves, among the species that would hone in on those carcasses, were hard hit.
Yellowstone was established as a national park in 1872. The U.S. Army arrived in Yellowstone in 1886 to protect the park and its wildlife from market hunting and other exploitation, staying through 1918. During that time period, wolf populations experienced a resurgence, prompting a concerted effort on the part of the Army to eradicate wolves from the park. That policy was carried on by the Park Service following the Army’s exit until 1926. The killing of the last two wolves by the Park Service occurred on a bison carcass near Soda Butte in 1926.
With gray wolves gone from the Yellowstone ecosystem, elk populations – free of their main predator – ballooned. More than twice as many elk grazed on Yellowstone’s northern winter range in 1932 than had in 1914. The belief that overgrazing on the northern range is harming vegetation and thereby causing erosion has persisted among some observers to this day.
Beginning in 1935 and carrying through 1968, elk, pronghorn and bison populations were artificially regulated by shooting or trapping conducted by park rangers. In the 1960s, new evidence suggested that the northern range was not being overgrazed and that elk populations could be selfregulating, with numbers on the northern range affected mainly by cycles of drought.
In 1966, the idea of wolf reintroduction was first posed to Congress as biologists expressed concerns over the high elk populations in Yellowstone. A wolf recovery plan team was established in 1974 and the first official recovery plan was brought before the public in 1982.
“One of the reasons that wolves were restored to the park was that park visitors said having wolves in the park would improve their experience and that wolves belonged in Yellowstone because they are native,” Bishop said. “And the population of elk was very high. There were people who considered that they were so high that the park was being mismanaged. “The entire dynamic of elk use of the landscape has been changed by the presence of wolves.”
Following the reintroduction in 1995-1996, elk populations have indeed shifted within the park. And numbers have declined. According to a report on the Yellowstone National Park Web site, “Computer modeling of population dynamics on the northern winter range predicts that 75 wolves would kill 1,000 elk per winter, but that elk would be able to maintain their populations under this level of predation, and with only a slight decrease in hunter harvest.” In a special edition of Yellowstone Science issued in 2005 documenting the first 10 years since wolf reintroduction,elk numbers had deceased about 50 percent from approximately 18,000 in 1993 to approximately 9,000 in 2005. Elk herds in the park dipped due to a variety of factors including predation from wolves and other carnivores, human hunting and possibly drought. A harsh winter in 1996-1997 was responsible for the death of thousands of elk, dramatically reducing the herd.
In the Yellowstone Wolf Project’s 2008 Annual Report, wolf predation numbers on elk in the northern range following 2000 averaged 0.9 elk per wolf per 30-day period. That report indicated elk populations on the northern range had dipped to around 6,000 in 2008 with wolf numbers just below 100.
Rick McIntyre of Silver Gate, a biological technician for the Yellowstone Wolf Project, said the decline in elk numbers has shown some positive signs for the ecosystem.
“I think it is fair to say that (the decline and redistribution of the elk population) was a gradual process and one that makes sense,” McIntyre said last Thursday while observing the Silver Pack in Lamar Valley. “Say the wolves have been here in Lamar Valley for a few weeks and have made several kills, then the elk seem to shift away from the area. Eventually, the wolves have to shift with the elk.
“The two species are interacting with each other and responding to one another.”
Elk on the northern range have shifted from congregating in large groups to smaller groups, often taking refuge in timbered areas rather than open swaths of country typical of the Lamar Valley. As a result, the spread of diseases among the elk population may be in decline as population density is more widely distributed in the park. The modified behavior of elk herds in the park has also impacted vegetation with populations of willow, aspen and cottonwoods on the rebound. Those vegetative species provide habitat for songbirds and beaver – another of Yellowstone’s keystone species.
“In general, you could say that for vegetation it is best for grazing and browsing animals to be on the move a lot,” McIntyre said. “If they stay in one spot, they pretty much eat everything and move on. Having the wolves back is a motivation for the elk to move on.”
The wolf reintroduction has also had an impact on many of Yellowstone’s other predators and scavengers Bishop . explained that, “one of the things that happens when a major keystone predator is removed from a system is that there is a phenomenon called a mesopredator release that takes place.”
The hypothesis of mesopredator release states that when a dominant predator is removed from a system, the medium-sized predators that have been suppressed by the dominate predator move into that niche.
“In the case of Yellowstone, that species is the coyote,” Bishop said. “Coyotes took over much of the role of wolves in the park. They were killing a number of elk in the northern range prior to the reintroduction of wolves. Coyotes were killing elk, cougars were killing elk, bears were killing elk. So the wolf stepped back into that role and modified the situation, for one thing taking the coyotes down to about half their prior number.
“What that did was reduce the coyotes influence on foxes, which they regularly kill because they are close predators. It also provided many more small mammals for other predators.”
The trickled-down effect of the wolf reintroduction has brought elk and coyote numbers more inline with healthy estimates for the ecosystem, and boosted the population of foxes, cougars and other predators.
Among the surprising benefits to Yellowstone and surrounding communities has been the economic impact of the wolf reintroduction. Even on the coldest days of winter dozens of wolf watchers gather in Lamar Valley for a chance to see the predators.
According to a two year study issued by John Duffield of the Department of Economics at The University of Montana in 2006, wolf watching in Yellowstone generates around $35 million for the local economy.
“It certainly has become a major factor, especially during the winter season,” McIntyre said. “It is a great thing for the local communities, because otherwise it might be a time of year when they are not getting a lot of business.” McIntyre, who spends hundreds of hours in Lamar Valley each season, has seen wolves everyday for more than eight years. He said the last time that no wolf sightings were reported in the park for an entire day was Feb. 8, 2001.
“One of the things that we simply had no clue about was how visible the wolves would be,” Bishop said. “That was pretty much a total surprise to all of us. I had no idea that we were going to be seeing wolves daily the way we are in Lamar. Three hundred-thousand or so people saw wolves in the park last year.”
Recently, the wolf ’s popularity with park visitors eclipsed that of Yellowstone’s other large predator – the grizzly bear. Wolves’ communal nature and visibility have factored greatly into the increased interest. Revered by some, loathed by others, the wolf ’s presence in Yellowstone – and the impacts of its presence – continues to evolve within the complex web of interactions between the park’s diverse plant and animal species. Still, nearly any conclusion drawn in the short frame of 15 years is subject to debate.
“Field studies are difficult at best, because there are so many variables,” Bishop said. “But, the field studies that are ongoing in Yellowstone are unparalleled in terms of any previous observations of wolves.”
Undoubtedly, conservation and controversy will continue to parallel the wolf ’s story in Yellowstone National Park.
Ben Pierce can be reached at bpierce@ dailychronicle.com and 582-2625.