15 Years Into Yellowstone National Park's Wolf Recovery Program
A deep chesty bawl echoes from rimrock to rimrock, rolls down the mountain, and fades into the far blackness of the night. It is an outburst of wild defiant sorrow, and of contempt for all the adversities of the world.
Every living thing (and perhaps many a dead one as well) pays heed to that call. To the deer it is a reminder of the way of all flesh, to the pine a forecast of midnight scuffles and of blood upon the snow, to the coyote a promise of gleanings to come, to the cowman a threat of red ink at the bank, to the hunter a challenge of fang against bullet. Yet behind these obvious and immediate hopes and fears lies a deeper meaning, known only to the mountain itself. Only the mountain has lived long enough to listen objectively to the howl of a wolf.
It tingles in the spine of all who hear wolves by night, or who scan their tracks by day. Even without sight or sound of wolf, it is implicit in a hundred small events: the midnight whinny of a pack horse, the rattle of rolling rocks, the bound of a fleeing deer, the way shadows lie under the spruces. Only the ineducable tyro can fail to sense the presence or absence of wolves, or the fact that mountains have a secret opinion about them. -- Aldo Leopold, Thinking Like a Mountain.
Deep in Yellowstone National Park's backcountry, our sleep and the predawn darkness was startled by a sound that long had been alien to the park. But on that mid-September day in 2008 the sound was unmistakable. A lone wolf had raised its muzzle to the sky and released a rich, baritone howl that pierced the inky stillness. A long-missing aspect of the park's wildness had very much returned.
There was no chance that my first visit to Yellowstone back in 1985 would have provided such an experience, as wolves had been extirpated from the park decades earlier, viewed as four-legged vermin that would decimate both Yellowstone's other wildlife as well as livestock in ranches and grazing allotments that rimmed the 2.2-million-acre park tucked into Wyoming's northwestern corner.
But 15 years ago, back in 1995, a dream of seeing wolves running wild in Yellowstone came to life, as the first of a handful or two of Canadian wolves were set free into the park. It was the culmination of a long-fought effort to see Yellowstone's ecosystem become whole once again with its complete prey and predator base. And it also was the beginning of a new chapter in the park's wildlife history. In those 15 years the wolf recovery program has succeeded far beyond expectations, both by repopulating the park with canis lupus, contributing to a reduction in the soaring population of the park's northern elk herd and, most unexpectedly, providing both researchers and park visitors with numerous glimpses of wolves.
Venture into the Lamar Valley on the park's northern range most any time of year and you're likely to spot a wolf or two. Come in late spring and you're likely to be rewarded not only with long looks at wolves returning from hunts, but, if you spend enough time in the valley, perhaps pups frolicking outside their dens. Back in January when I visited the park Rick McIntyre, a part-time ranger who arguably has spent more time than anyone panning the valley with his binoculars and spotting scopes to supplement his already-rich knowledge of wolves, noted that the last time no one saw a wolf anywhere in Yellowstone was back on February 8, 2001.
"This has become the best place in the world to see wolves," said the ranger.
More proof of that came the very next day when I encountered two visitors from Connecticut spotted a wolf trotting through the Upper Geyser Basin near Old Faithful, and a ranger told me of hearing it unleash a howl of its own.
While the recovery program has struggled at times -- wolf No. 10, the alpha male of the Rose Creek Pack that was among the first 14 wolves brought into Yellowstone in January 1995, was shot and killed, states surrounding the park have put wolf recovery in jeopardy, mange and distemper have swept through some of the park's packs -- it largely has been an overwhelming success.
Doug Smith, project leader of Yellowstone's Wolf Project, says overall wolf numbers in the park, estimated currently at 96-98 animals, are down from highs that approached nearly 200 back in 2007, but doesn't believe the decline will continue.
"We’ve experienced recent population declines, and that’s got everybody concerned. The decline is what we’re calling natural, so it’s not cause for alarm, but the population declined from ‘07 to ‘08, and then again from ‘08 to ‘09," the wildlife biologist said in a recent interview. "So that’s our first decline in back-to-back years in the 15 years that wolves have been back in Yellowstone. We had two other declines, one in ‘99 and one in ‘05, but the next year was a rebound year. Those other declines were associated with the disease canine distemper, and it killed a lot of pups. So the year following the disease, we had a bounce back."
While there has yet to be an agent identified for the recent decline, which equated to a loss of about 26 wolves from 2008's population, Dr. Smith believes it could simply be tied to dropping elk numbers.
"We think the wolves are coming into equilibrium with the elk population," he said. "In other words, they overshot what the park could support and now they’re declining more in measure with what they can be supported by in the park."
Elk in Yellowstone were burgeoning in the early 1990s, with the Northern Herd peaking at roughly 20,000 animals in 1992. Of the park's eight elk herds, the biologist said five are stable or increasing, while the other three are in decline. The Northern Herd has dropped the most, by about 50 percent, since wolves returned to the park, he noted, quickly adding, however, that the drop cannot be attributed entirely to the return of the wolves.
“Of course, everybody blames that on wolves, and certainly wolves play a part, but they’re not the only part," the biologist said. "We did a calf-elk mortality study, and 50-60 percent of the elk calves are killed by bears. We also have cougars, and cougars have a higher per capita kill rate than do wolves. We've got two bear species, cougars and wolves, so we’ve got a lot of predators. And secondly, the state of Montana disagreed with Yellowstone Park as to the proper number of elk. They thought 20,000 was too many, so when the elk migrate out of the park in winter, they harvest a lot of cow elk, with the objective of lowering the herd size.
"So they achieve that object through hunting. And then we’ve had a drought, and we’re seeing that this drought is affecting elk condition. And making elk more vulnerable to attack by predators. So, do wolves have a role in this decline? Oh, you bet," said Dr. Smith. "But are wolves the only agent? Absolutely not. And we would never know this, but I would say if wolves are the only issue, we would not have seen a 50 percent decline, because other systems that only have wolves as the predator, wolves never exert as much influence as that, and so I do get a little defensive when people say this is all due to the wolves. I don’t deny the effect of wolves, but I do defend against the over-statement that this is all wolves.”
If the decline in the Northern Herd is impacting wolves' hunting success, that could be playing a role in how great an effect disease has on the predators. In recent years mange, distemper, and parvovirus hit various packs in the park.
“Mange is a nagging, unpredictable killer that is not catastrophic," said Dr. Smith. "So distemper, when it swings through, kills 80 percent of your pups. Mange, wolves get it, but that doesn’t necessarily mean they’re going to die. Mange is very dependent upon the animal’s immune system, so if you’re healthy, you get a mild case and you shake it off and you recover. The animals that have compromised immune systems typically are pups and old animals. They can get a really bad case of it.
“If you’re food-stressed, your immune system may not be up to snuff," he said. "So we have had some mortality due to mange, no question, but it’s a dead wolf here and there. And the worst I’ve heard mange do is to stop population growth, but not turn it negative."
In an effort to determine if there's some biological reason the wolf population declined, the biologist and his colleagues regularly monitor the health of wolves throughout the park.
“We catch 20-25 wolves a year, and we pull blood," Dr. Smith explained. "In that blood we can assess disease exposure, we can assess genetics, we can assess condition. And we’ve done all those things, and then we are watching from afar as well, piecing it all together.”
When asked what surprised him most of the recovery program over the past 15 years, the biologist was quick to say, "We never thought it would go so well."
"I mean, here we are 15 years in and we’ve got a declining wolf population because they went too high. The other thing is no one thought they would be as visible as they are. We routinely watch them from the road, and these are wild wolves. So we’re really able to get insights into things people have never gotten insights too before," he said, explaining that the high visibility has enabled them to learn much about wolf behavior, particularly when it comes to hunting and "(H)ow they kill elk and bison and how it’s different between elk and bison."
"We’ve seen hundreds of attacks. Most people in other areas have seen two or three. Rolf Peterson, who’s been studying wolves for 40 years, has seen 12 kills in his life," said Dr. Smith. "We’ve seen pushing 100 (kills) and probably 300 or 400 chases. How do they interact with coyotes and grizzly bears? Those are type things that you gather data on indirectly. We’re watching them! Pack dynamics. They’re a very social animal. Sitting and watching their social behavior, studying their howling. Howling has always been studied by listening to them howl, not seeing what they’re doing while they howl. So the opportunity to see them has really advanced the yardstick with what we’ve known about wolves.”
In talking with Ranger McIntyre back in the Lamar Valley, he pointed out that it can take upwards of 14 hours and 15 wolves to kill a single bison. Elk, however, can be killed in 4 minutes, he added.
"Elk typically run when wolves approach, bison typically stand. So you’ve got a problem there," noted Dr. Smith. "You’ve got to work out a different tactic. And we think -- this is not completely elucidated yet -- that you need to have a different pack composition to kill bison vs. elk. For example, we have learned watching wolves kill elk that big, large mature male wolves are better at the task of killing then are small males and females, because they don’t have the same body size. But it appears that you only need one big male to be good at killing (elk).
"With bison, it appears that you need multiple big males because bison are twice the size of an elk, and they stand their ground," he continued. "You need huskier, stronger animals. And the bison kills I’ve seen, I’ve seen up to four big males ripping and tearing at the same bison and you won’t often see that with elk.”
The difference in prey has produced a somewhat larger killing machine in Yellowstone's interior, in the Pelican Valley and along the Firehole River. In these areas wolves hang behind in the fall when the elk head to lower wintering grounds. Throughout the winter months, the wolves -- which Dr. Smith said are about 5-10 percent larger than those that prey on elk through the winter; one male from Mollie's Pack weighed 144 pounds -- survive by preying on bison.
"The pack that lives in Pelican Valley kills nothing but bison all winter. In the summer they switch back to elk, because the elk return. If you get a choice, you’re going to take elk," said Dr. Smith. Why the wolves don't follow the elk isn't known, he added, but what is known is that the wolves have figured out how to effectively kill bison.
"They have that skill now, they know how to do it, and when elk leave they just stick and kill bison. That’s what they’ve been doing the last few years. They just start whacking bison as soon as the elk leave. And that pack, as well as the one that lives in the Firehole, has more large males than any other pack in the park," said the biologist.
More chapters remain to be written in the story of wolf recovery in Yellowstone. Will the current decline in population be reversed? Will the state of Wyoming arrive at a management plan that ensures the survival of wolves in the park? Will the park's packs serve as a source of wolves for elsewhere in the Rockies, as already dispersers have been traced to northern Utah and northern Colorado near Rocky Mountain National Park. One thing remains sure to be woven through those chapters -- the stigma that some see in the breed.
"It seems that wolves can never be left alone. Not that they need to be, but they’re inordinately meddled with," said Smith. "The controversy just keeps getting worse and the most concerning thing is it’s kinda a war of values, where facts don’t matter. It’s political power against political power. Rationale debate, open discussion is a casualty, and that concerns me. It’s 15 years into it, I thought by now there would be a modicum of calm. ‘Alright, this is over, we know they’re here, let’s move forward and try to deal with this.’
"It’s as hot as it’s ever been.”
To listen to a podcast of this interview, click here.
Some great websites for following Yellowstone's wolf recovery:
U.S. Fish and Wildlife Service, Gray Wolves in the Northern Rocky Mountains: http://www.fws.gov/mountain-prairie/species/mammals/wolf/
Greater Yellowstone Science Learning Center: http://www.greateryellowstonescience.org/topics/biological/mammals/wolves
Ralph Maughan's Wildlife News: http://wolves.wordpress.com/category/wolves/