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Will The Fairy Tale Mentality Of Western States Against Predators Hamper Their Ability To Slow Chronic Wasting Disease?
by Todd Wilkinson
Photo courtesy NPS / Jacob W. Frank
For over two decades, Douglas Smith and successive teams of researchers have watched wildlife predators hunting for prey in Yellowstone.
The national park’s senior wolf biologist says there is no mistaking the way that lobos identify and target elk. To the human eye, an individual wapiti might appear perfectly healthy yet there is something—almost a sixth sense— that catches the attention of discriminating pack members searching for their next meal.
It might be an elk with arthritis carrying a slight gimp in its gait, or maybe a hint of winter-worn fatigue, a slowness brought on by advancing old age or illness, or perhaps naïve behavior exhibited by the young.
There is no doubt, based on the accrued record of wolf behavior documented in Yellowstone—and the significant body of scientific accounts logged across the continent—that under normal conditions, wolves key-in on prey that is meek, infirmed or vulnerable.
“Wolves pick up on stuff we can’t see. They are most efficient at exploiting weaknesses in prey because their survival depends on it,” Smith told me recently. “They are predisposed, by instinct and learned behavior, to focus first on animals that are easier to kill rather than those living at the height of their physical strength.”
Does having predators on the landscape—wolves, bears, mountain lions and coyotes— provide a protective gauntlet that can help slow the spread and prevalence of deadly diseases?
In particular, with ultra-lethal Chronic Wasting Disease now invading the most wildlife-rich ecosystem in America’s Lower 48 states and spreading coast to coast, are these often maligned meat-eaters, frequently dismissed as worthless vermin in western states, actually important natural allies in battling CWD?
While the data and the assessments of most scientists clearly suggests yes, there remains fierce resistance by some to acknowledge the beneficial roles predators play. At the recent year-end meeting of the Montana Fish and Game Commission, anti-predator biases were on full display, especially toward wolves. They surfaced as the commission pondered its next move in confronting CWD which this autumn entered Montana via sick wild deer for the first time in state history.
Weeks earlier, Ken McDonald, wildlife bureau chief at the Montana Fish Wildlife and Parks Department, raised eyebrows when he claimed the advantages predators bring in weeding out sick prey is merely theoretical and unproved. Dismissing the notion of wolves as effective disease-fighters, he asserted that in order for lobos to truly make a difference in slowing CWD’s advance, they would need to exist in such high numbers that it would be socially unacceptable to humans, namely ranchers and hunters.
In terms of Montana’s strategy for dealing with CWD spread in the state through sick wildlife entering via Wyoming from the south and Canada to the north, McDonald said the state’s primary method of confronting disease will involve enlisting hunters to aggressively harvest animals in emerging CWD endemic zones. The state recently approved the issuance of 1,200 additional B tags to kill deer in areas east of Red Lodge, Montana (the northeast corner of Greater Yellowstone) where six dead deer have turned up CWD positive out of 1300 tested there—four mule deer bucks, a mule deer doe and a white-tailed doe.
Many claim McDonald’s characterization of wolves demonstrates not only a personal anti-wolf bias, which also permeates the thinking of the department, but it shows a lack of understanding and appreciation for the natural history of the species. In other words, it denies what the very essence of a wolf is.
“I was disappointed with Ken McDonald’s nonsensical bureaucratic response,” conservationist and professional biologist Dr. Gary J. Wolfe wrote recently in comments that were widely circulated.
Wolfe is a former Montana Fish Wildlife and Parks Commissioner appointed by Gov. Steve Bullock. Notably, he is also the former project leader of the CWD Alliance founded by a number of prominent sportsmen’s’ groups and former national president and CEO of the Rocky Mountain Elk Foundation for 15 years. He is widely respected in hunting circles.
“While I don’t think any of us large carnivore proponents are saying that wolf predation will prevent CWD, or totally eliminate it from infected herds, it is ecologically irresponsible to not consider the very real possibility that wolves can slow the spread of CWD and reduce its prevalence in infected herds,” Wolfe says. “We should consider wolves to be ‘CWD border guards,’ adjust wolf hunting seasons accordingly, and let wolves do their job of helping to cull infirm animals from the herds.”
Strong evidence seems to bear him out. Not only do predators stalking large game species target weak animals, they can mitigate the impact of disease outbreaks, experts say. Further, by removing sick prey species, predators could, over time, though this is unproved, make herds more resilient and stronger, less susceptible to disease.
While some may doubt this premise, illustrated in literature below, no one has provided evidence suggesting that having robust and stable numbers of predators will not aid in confronting the most rapidly spreading and fearsome new disease in North America.
The Greater Yellowstone Ecosystem is a region unparalleled in the Lower 48 states. It is known globally as America’s Serengeti for having its full original complement of mammal and bird species, including large native predators, that were here when Europeans arrived on the continent in the late 15th century. Plus, the landscape these animals inhabit, a 22.5-million-acre mixture of private and mostly public land, is intact—meaning not fragmented and enabling migrations of elk, deer and pronghorn (antelope) to occur and which do not exist anywhere else.
Lloyd Dorsey, conservation director for the Sierra Club in Wyoming, is a hunter and crusader against Wyoming’s operation of elk feedgrounds. This autumn when we spoke about predators and CWD, he had just returned from hunting in the Gros Ventre mountains east of the National Elk Refuge. He told me of how on the morning that he glassed mule deer and bands of elk, he found grizzly tracks in the snow and heard wolves howling a quarter mile away.
Citing reams of scientific studies to back him up, Dorsey says predators play an import ecological role in keeping prey species in check and in serving as vanguards in removing sick animals. Greater Yellowstone’s “predator guild” of wolves, grizzly and black bears, lions and coyotes, he notes, also makes it a draw for wildlife watchers from around the world, helping to fuel a $1-billion annual nature-tourism economy tied to the national parks alone.
A disease like CWD that stands to significantly harm the health of deer family members over time—deer, elk, and moose—also has potentially grave implications for species that eat and scavenge their remains. In many ways, the biological integrity of Greater Yellowstone’s large mammal populations depends upon the health of its ungulate herds and the biomass they provide in sustaining other species large and small—those with fur and feathers down to the microbial level. Diseases that threaten to dramatically diminish Greater Yellowstone’s ungulates could have negative, far-reaching consequences for people and the environment.
To date, there is no evidence that CWD can infect predators, humans or livestock, though geneticists who have studied the molecular make-up of CWD prions [misshapen proteins] believe it could change. And a recent study in Canada involving macaques exposed to CWD prions has elevated concerns. Macaques are primates with genes similar to humans.
With CWD, Wyoming is perilously burning the candle at both ends and it has implications for Montana and Idaho, Dorsey says. Wyoming and the U.S. Fish and Wildlife Service continue to knowingly operate feedgrounds [read parts One, Two and Three of MoJo’s series here] which makes the state and federal government guilty of game management malpractice by setting up public wildlife for calamity, he says.
At the same time, Wyoming persists in destroying a natural ally—wolves—based upon no solid reason other than traditional cultural animosity toward these archetypal animals that earlier generations of settlers took great delight in eradicating to make way for livestock.
“Our understanding of wolves has broadened in an age of greater scientific and ecological awareness,” Dorsey told me. “They are not the animals of menacing myth they were portrayed to be in fairy tales. We can—and should—co-exist with them for mutual benefit.”
Nonetheless, Wyoming—along with Alaska—is known for having the most notoriously-hostile attitude toward wolves in America. There, in over 85 percent of the state, lobos, like coyotes, can be killed year-round for any reason, no questions asked. Only in the northwest corner of Wyoming within the vicinity of Yellowstone and Grand Teton national parks are wolves classified as a game animal and even there it is state policy to keep their numbers suppressed to please outfitters, guides and ranchers.
Beyond that small zone, they are classified as “predators” and treated as vermin. They can be trapped, poisoned, shot at any and all hours of the day, and targeted by aerial gunners in aircraft. Even if they are not threatening livestock, it’s open season on wolves.
The profound irony is that just as Wyoming condones a campaign of re-eradication against wolves, CWD has been rapidly spreading westward, faster than anyone expected across the state via infected mule and white-tailed deer.
Perfect conditions to amplify a CWD pandemic, experts say, exist on the National Elk Refuge and 22 elk feedgrounds operated by the state of Wyoming, many of them on U.S. Forest Service land.
CWD’s arrival is considered imminent. When the disease lands in the Wyoming feedgrounds, where more than 20,000 elk are unnaturally concentrated during winters, CWD is expected to not only take hold but have its spread accelerated due to the widely-condemned management practice of bunching up wapiti. The conditions there are similar to game farms where CWD infections have been devastating.
This point was made in a letter sent December 7, 2017 from the Montana state wildlife commission (read it at bottom of this story] to counterparts in Wyoming, asking the state to take steps to shut down feeding.
“We respect the fact that how Wyoming manages its affairs is up to Wyoming. However, Montana’s ability to combat CWD will depend upon decisions that Wyoming makes about its wildlife management. Over the long-term, the feed grounds make your wildlife populations less healthy, less stable, and much more vulnerable to a catastrophic disease event,” the Montana Fish and Wildlife Commission wrote. “We implore you to begin the process of looking at alternatives to the present management regime that unnaturally concentrates wildlife in feed grounds each winter and increases the pace at which CWD infects both states’ wildlife populations.”
The letter ends with this warning: “If we do not address CWD, we will all be culpable in leaving a greatly devalued landscape to future generations.” Culpable is a word with many connotations.
While Montana has escaped the intense scrutiny and public rebuke aimed at Wyoming over its operation of feedgrounds and controversial management of wolves, Wolfe and others say Montana isn’t much better with regard to predators.
Recently, another case of CWD was confirmed in a deer near Chester along Montana’s Hi-Line south of Canada.
Currently, only three wolf management units in Montana have strict quotas (two located north of Yellowstone and one west of Glacier National Park). But all others allow unlimited wolf harvest “which is probably not the best ecological strategy for containing CWD,” Wolfe noted. “As a wildlife biologist who spent several years working on the CWD issue, I believe wolf predation is an important tool that needs to be recognized and effectively utilized, along with other tools, as part of Montana’s CWD management plan.”
Wolves, Wolfe says, ought to have their numbers safeguarded in areas that represent the front line of disease. Stable packs can serve as a barrier. Wolf management units (WMUs) that border CWD infected areas (or have CWD infected herds within the WMU) should have conservative wolf harvest quotas, he notes. Currently, only three WMUs have quotas (313 and 316 immediately north of Yellowstone, and 110 west of Glacier). All others allow unlimited wolf harvest.
When the argument has been presented to the Wyoming Game and Fish Department, it has been met with deaf ears, though Dr. Mary Wood, the state wildlife veterinarian noted in 2016 that predators can play a beneficial role.
Humans can invent any fairy-tale-reason they want to despise wolves and justify their elimination, but that doesn’t change the fundamental time-tested nature of the species, says Kevin Van Tighem, a hunter and former superintendent of Banff National Park in Alberta’s Canadian Rockies. “I don’t know of a single credible biologist who would argue that wolves, along with other predators and scavengers, aren’t important tools in devising sound strategies for dealing with CWD.” Van Tighem says it can be rationally argued that wolves provide the best line of defense since they are confronting infected animals.
Van Tighem told me, just as a dozen other scientists and land managers who hunt have—that once CWD is confirmed in the places where they go afield, they will no longer eat game meat from that area and may stop hunting altogether.
Dr. L. David Mech, the eminent American wolf biologist, has authored or contributed to hundreds of peer-reviewed scientific papers on wolves and prey. We’ve been talking about wolves since the late 1980s when he came to Yellowstone in the years before lobos were reintroduced. There’s no tangible argument he’s seen that suggests wolves wouldn’t be useful in combatting CWD.
“In the main, the preponderance of scientific evidence supports the view that wolves generally kill the old, the young, the sick and the weak,” Mech said. “There’s so much documented field data behind it.”
He then made a point that exposes the limitations of relying on human hunters and sharpshooters alone to remove suspected CWD carriers. Wolves appear to target sick animals that, to the human eye, exhibit no overt symptoms of disease.
“There’s a lot more going on than we can detect,” Mech said. “They are killing animals that most people would say, ‘That animal looks pretty healthy to me,’ but in fact it isn’t.” Mech stays out of the political fray, though he says the value of predators is clear. “Based upon everything I’ve seen over the course of my career, I generally stand behind the assertion that wolves make prey populations healthier,” he said. “The evidence to support it is overwhelming.”
In Wolves on the Hunt: The Behavior of Wolves Hunting Wild Prey, Mech, Doug Smith and co-author/editor Daniel R. MacNulty undertook an exhaustive, unprecedented review of scientific studies and observations related to wolf behavior. They cite example after example of how wolves choose prey. They use intricately-detailed observations based on the work of park ecologist Rick McIntyre and colleagues who have tracked the wolves of Yellowstone’s Lamar Valley for decades. They also point to hours upon hours of accumulated video footage amassed by award-winning wildlife cinematographer Robert Landis who has recorded numerous wolf predation incidents in Yellowstone.
“Suffice it to say here, in summer, that it is well documented…that wolves generally kill calves, fawns and older members of prey populations along with individuals that are diseased, disabled, or in poor conditions or that have various abnormalities,” the authors noted. “These types of individuals are physically less able to withstand long and persistent attacks like more healthy animals can.”
In 2003, then Denver Post reporter Theo Stein interviewed scientists about CWD spreading though deer and elk in Colorado. Dr. Valerius Geist, who briefly became a darling of anti-wolfers when he raised the issue of tapeworms, made this assertion about the significance of wolves in containing CWD spread via proteins called prions. “Wolves will certainly bring the disease to a halt,” Geist said. “They will remove infected individuals and clean up carcasses that could transmit the disease.”
The impacts of historic predator-killing campaigns have been documented.
Stein added that “Geist and Princeton University biologist Andrew Dobson theorize that killing off the wolf allowed CWD to take hold in the first place.” Further, the Chronic Wasting Disease Alliance observed, “The spread of chronic wasting disease toward Yellowstone’s famed game herds alarms wildlife lovers, but two top researchers think biologists will discover a powerful ally in an old frontier villain. The wolf.”
Be it wolf, mountain lion, bear or coyote, each different predator species has different approaches to both taking prey and scavenging. Besides the significant body of evidence in the Mech-Smith MacNulty book, there is a lot of brainpower that has been applied to thinking how predators could help head off CWD.
Mountain lions are known for being ambush predators, lying in wait to target mule and white-tailed deer. Wolves and coyotes are “coursers” meaning they chase prey across open ground. Grizzlies and black bears take elk calves and deer fawns and, like the others, feast upon freshly killed carcasses, cleaning them down to the bone. Of note is that Mech and others have documented that wolves, for example, take down larger numbers of deer bucks, which, according to CWD researchers, also have a higher level of CWD prevalence in wild herds.
In a 2010 peer-reviewed journal article, “Mountain lions prey selectively on prion-infected mule deer,” lead author Caroline E. Krumm with the Colorado Division of Wildlife’s scientific research center and four colleagues noted how cougars appeared to select for CWD-infected deer because they were easier to fell. Their research examined 108 kill sites where the big cats ambushed deer.
“From the observations gathered across several studies, we hypothesize that although much of the ‘selection’ we observed may be attributed to infected mule deer being less vigilant or fit and thus relatively vulnerable to ‘attack’ of one kind or another, mountain lions may also learn to recognize and more actively target diseased deer,” they wrote.
Echoing Mech’s observations, they pointed out “other studies indicate that coursing predators like wolves and coyotes select prey disproportionately if they appear impaired by malnutrition, age or disease.”
Just as other scientists have warned that once CWD becomes firmly established in wildlife population and its effects over time can be dire, Krumm and co-authors suggested predators can help minimize prion contamination.
“Although theory suggests that removing infected animals could ‘sanitize’ and slow the rate of prion transmission, prevalence can be remarkably high in mule deer populations preyed upon by mountain lions. Prion transmission among deer can occur via several mechanisms, including indirect transmission from exposure to prions in the environment,” they stated. “We observed that mountain lions typically consumed greater than 85 percent of a deer carcass, often including brain tissue, and this may be beneficial in decreasing prion contamination at kill sites. However, the extent to which selective predation by mountain lions alters the dynamics of prion disease epidemics in natural mule deer populations remains unclear.”
That’s why it’s important to have the full predator-guild present, perpetually seeking out sick animals in different ways, in different parts of the landscape.
In 2006, researcher N. Thompson Hobbs wrote “A Model Analysis of Effects of Wolf Predation on the Prevalence of Chronic Wasting Disease in Elk Populations of Rocky Mountain National Park.”
There, he created a simulation based upon meat consumption necessary to sustain a group of wolves and factoring the likelihood they would first target sick animals. Just as experts who deal with epizootic diseases warn that the Wyoming feedgrounds represent the worst possible conditions for CWD to take hold, likely to unnaturally accelerate an outbreak, wildlife predators can serve as a powerful counterbalance.
Hobbs lays out how it works. “Increased mortality rates [by predators] in diseased populations can retard disease transmission and reduce disease prevalence. Increasing mortality slows transmission via two mechanisms. First, it reduces the average lifetime of infected individuals. Reduced lifespan, in turn can compress the time interval when animals are infectious, thereby reducing the number of infections produced per infected individual,” he writes. “The effect of reduced intervals of infectivity is amplified by reductions in population density that occur as mortality increases, reductions that cause declines in the number of contacts between infected and susceptible individuals. Both of these mechanisms retard the transmission of disease. If these mechanisms cause the number of new infections produced per infected individual to fall below one, then the disease will be eradicated from the population.”
Granted, his analysis focused on Rocky Mountain National Park and Colorado where there is today a population-level outbreak of CWD under way and where there are no wolves. Rocky Mountain has densities of wapiti approaching 115 elk per square kilometer. The unnatural densities of elk on the Elk Refuge and Wyoming feedgrounds, Dorsey notes, are orders of magnitude greater, literally thousands of elk per square kilometer. It means that should CWD take hold, predators would be even more important in aiding to stop a potentially virulent spread.
According to one study, CWD rates in Rocky Mountain were as low as one percent in the early 1990s. Since 2008, the proportion of female elk infected with CWD in the park has fluctuated between six and 13 percent. CWD is today the leading cause of death in adult female elk.
Despite claims that predators decimate big game herds, there is, in fact, little evidence to back up those assertions, broadly speaking. It’s true that under certain circumstances the presence of predators can result in a significant population decline compared to numbers of ungulates present after species like wolves were eradicated. However, predator sinks are gross anomalies in the Rocky Mountain West; moreover, ecosystems are dynamic and populations of all species are always in some kind of flux.
Again, based upon surveys compiled by state wildlife agencies in Wyoming, Montana and Idaho, most elk hunting units—with wolves inside them—are at, close to, or above desired population goals for wapiti. Hunter success is high, especially for hunters willing to work at stalking their prey. Outfitters/guides throughout the tri-state region tout hunter success and boast of having happy customers.
What anti-predator voices never acknowledge is that the very prey species they covet—large, muscular bull elk and deer bucks—are products of thousands of years of evolution and pressure applied by predators, ecologists note. Pronghorn (antelope) on the prairies are fleet of foot because, as a result of survival of the fittest, they became biologically engineered to outrun North America’s version of African cheetahs before those big cats went extinct.
McDonald of Montana Fish Wildlife and Parks has asserted that human hunters will be deployed to eliminate CWD. In Wisconsin, the state has spent millions of dollars depopulating areas of white-tail deer and enlisted hunters to remove animals in an effort to knock CWD back, all to no avail. CWD has spread from Wisconsin into both Minnesota and Michigan.
In 2011, Dr. Margaret Wild collaborated with Hobbs and two other authors on a paper, “The Role of Predation in Disease Control: A Comparison of Selective and Nonselective Removal on Prion Disease Dynamics in Deer.” This study was based on a model that examined the likely effects of wolf predation on CWD-infected deer and holds possible implications for states in the Upper Midwest. The simulation noted that wolves could prevent CWD from emerging at the population level and proliferating. Crucial is allowing predators to perform their role in the early stages of the disease’s arrival.
“Thus far, control strategies relying on hunting or culling by humans to lower deer numbers and subsequently CWD prevalence have not yielded demonstrable effects,” they wrote, explaining that human hunters only remove sick deer randomly while predators actively seek out the infirmed.
“Doubling the vulnerability of infected animals to selective predation accelerated the rate of decline in prevalence,” they noted, even encouraging the consideration of making sure predator populations were healthy in the forward zones of disease progression.
“We suggest that as CWD distribution and wolf range overlap in the future, wolf predation may suppress disease emergence or limit prevalence,” they added.
The noted American-Canadian mammal biologist Dr. Paul Paquet has been monitoring the geographic expansion of CWD relative to the presense of long-established wolf populations since the disease was first confirmed in the wild decades ago.
“To date and in general, CWD has not thrived where wolf populations are active, although the disease has appeared on the margins of these populations. A simple mapping of the distribution of wolves and CWD is very instructive,” Paquet told Mountain Journal. “I have not mapped the distribution of all large predators and CWD, but that would be an instructive exercise. In particular, a comparison of diverse multi-prey and multi-predator systems like Yellowstone with simpler systems like the Great Lakes would of interest, as well as comparing the mix and densities of predators with establishment of CWD.”
Why is confronting anti-wolf bias as important as the significant body of evidence pertaining to predators and CWD? Because the opinions that are informing policy don’t align with reality.
Here, it is essential to provide some context of wolf presence in the West, more than two decades after Canis lupus was reintroduced to Yellowstone and the wilderness of central Idaho and since they have fanned out across a much wider area, reaching Oregon and Washington and possibly opening discussions of their return to Colorado.
In 2016, a record 243 livestock animals—154 cattle, 88 sheep, and a horse—were killed by wolves in Wyoming which a year ago had an estimated minimum wolf population of 377. Montana’s wolf count is close to 500 and Idaho had 786 in 2015, according to the U.S. Fish and Wildlife Service.
The Fish and Wildlife Service no longer compiles a regional report for the northern Rockies/Pacific Northwest since wolves were removed from federal protection and management handed over to the states.
Wolves account for about 1 percent of total livestock losses. Noteworthy is that only 62 of the 300-plus wolf packs in the western U.S. were involved in livestock depredation and the majority of those cases involved only a handful of livestock depredations at most. “What it means is that four of every five packs are existing without incident,” former federal wolf biologist Michael Jimenez said.
Before he retired as the Fish and Wildlife Service’s wolf field director, Michael Jimenez and I spoke annually about wolf losses—real and imagined—and this gets at McDonald’s point about social tolerance and its connection to political rhetoric.
In April 2015, 36 Republican House members sent a letter to then Interior Secretary Sally Jewell and Fish and Wildlife Service Director Dan Ashe demanding wolves be delisted across all of the Lower 48. “Since wolves were first provided protections under the Endangered Species Act, uncontrolled and unmanaged growth of wolf populations has resulted in devastating impacts on hunting and ranching, as well as tragic losses to historically strong and healthy livestock and wildlife populations,” those members of Congress wrote.
The phrase “devastating impacts on hunting and ranching, as well as tragic loses to historically strong and healthy livestock and wildlife populations” is, on the face of it, a fabrication. How?
In one of the last reports Jimenez compiled, he noted that at the end of 2014 there were an estimated 1,800 wolves comprising roughly 313 packs. Across Wyoming, Idaho, Montana, Oregon and Washington, all those wolves in that year were confirmed to have killed a total of 140 cattle, 172 sheep, four dogs, one horse and one donkey. In a vast region where there are millions of cattle, sheep, dogs, horses and donkeys — and thousands of ranchers and farmers — is this what members of Congress mean by “devastating” and “tragic”?
Across the West, thousands upon thousands of domestic cows and sheep perish each year from disease, weather, accidents, eating poisonous plants, lightning strikes and predation of all kinds, including killing by feral dogs. Wolves account for about 1 percent of total livestock losses. Noteworthy is that only 62 of the 300-plus wolf packs in the western U.S. were involved in livestock depredation and the majority of those cases involved only a handful of livestock depredations at most. “What it means is that four of every five packs are existing without incident,” Jimenez said.
° ° °
Those who possess a disdain for wolves have, for years, thrown up a series of theories, all either discredited or unsubstantiated. The first was that wolves would decimate big game herds. Fact: it hasn’t happened and most big game populations in wolf country are at or above population objectives. Click here to get the 2017 elk outlooks for Montana, Wyoming, and Idaho. Recently, an analysis conducted by the Washington Department of Fish and Wildlife showed that wolves in the eastern part of that state were not harming populations of deer, elk, moose and bighorn sheep.
Another claim is the lobos reintroduced from Canada were the “wrong subspecies” and substantially different from wolves that existed in Greater Yellowstone and central Idaho prior to their extermination. Fact: also not true. Click on video here that addresses that contention.
More recently, as those notions have been dismissed as absurd, two new contentions have been advanced. There’s one claim that wolves represent an imminent danger to humans, pets and wildlife health because they carry Echinococcus granulosus, a tapeworm linked to hydatid disease. Not only is this dismissed as untrue and fear-mongering, but the tapeworm is found widely in elk, deer and moose. Hunters are advised to take precautions such as wearing gloves in field dressing animals.
The latest unproved charge, raised again at the Montana wildlife commission meeting, is that wolves may themselves be vectors for spreading CWD because they eat disease-infected elk and deer and might therefore disperse prions via their scat. Opinion is divided on whether prions, being hardy agents, can survive passage through a wolf, or bear, coyote, or mountain lion’s digestive track. It’s possible.
Nonetheless, ecologists say that the role of predators in removing CWD-infected animals and “cleaning-up” carcasses by scavenging them would more than likely offset any negative potential they have for dispersing CWD more widely via scat. Migratory deer and elk already are already moving hundreds of miles seasonally across and between vast expanses of land, shedding CWD prions into the environment along the way via urine, feces, saliva and decomposing tissue when they die.
Critics say the denial coming from western states about the beneficial role predators can play in slowing the advance of CWD is driven by a backward cultural mindset—reinforced by politicians who perpetuate it to get elected—that has little or no scientific basis. In the case of CWD, states that continue to adhere to anti-predator policies may, in fact, be making disease impacts worse.
Adds Dorsey, “At this urgent moment, when everyone is scrambling to do what’s sensible, now is not the time to be killing off the very biological tools we need.”
CWD is literally at the gate of Yellowstone and its arrival has park officials worried.
A decade ago, P. J. White and Troy Davis provided an overview of CWD for an article that appeared in the journal Yellowstone Science. Referencing the study by Wild and Miller, and noting that wolves could have “potent effects” in tamping down CWD prevalence, they wrote, “Wolves [in Yellowstone] are highly selective for elk throughout the year and bears are highly selective of neonatal elk during summer. If predators can detect CWD-infected animals, then selective predation and quick removal of carcasses by scavengers could reduce CWD transmission rates and, in turn, the prevalence and spread of the disease. Wolves could also reduce the risk of transmission by dispersing deer and elk.”
With predators on the landscape, again based on simulations run at Rocky Mountain National Park, “compensatory and density-related effects could result in less net mortality than rates of infection and death from CWD would suggest. Thus, the net effect of CWD on the abundance, reproduction, and survival of deer and elk could be less than predicted based on data collected in areas with few large predators.”
Many scientists say that Greater Yellowstone’s full predator guild represents a formidable gauntlet to CWD.
In March 2016, Yellowstone assembled its “Chronic Wasting Disease Surveillance Plan”. Looming large in the document is this acknowledgment by the three authors Chris Geremia, John Treanor, and P. J. White: “If epidemics lead to widespread population reductions in Yellowstone, CWD could indirectly alter the structure and function of this ecosystem during future decades; adversely affect species of predators and scavengers; and have serious economic effects on the recreation-based economies of the area.”
The authors note that Yellowstone, by law, is mandated to confront diseases that threaten its mission to promote the persistence of native species, but CWD represents a conundrum. “A primary purpose of Yellowstone National Park is to preserve abundant and diverse wildlife in one of the largest remaining intact ecosystems on earth. Disease management actions such as depopulation or substantial population reductions by random culling may be inappropriate for the park because they would remove many more healthy animals than infected animals, substantially reduce the prey base for predators and scavengers, and result in fewer benefits (e.g., scientific knowledge) and reduced visitor enjoyment (e.g., recreational viewing).”
No strategy has been effective at eradicating CWD from areas where the disease is present. Disease management objectives will focus on early detection and monitoring,” park officials say. Yellowstone in summer is a mixing bowl where as many as 20,000 deer and elk from multiple herds converge, including animals from the Jackson Elk Herd that winters on the National Elk Refuge and state feedgrounds. Those animals, in turn, mix with tens of thousands more.
Yellowstone, along with officials in Montana, Idaho, the Elk Refuge and Wyoming state feedgrounds are on the lookout for sick-looking animals, testing carcasses of dead animals and even removing asymptomatic elk. Wolves, lions, and coyotes are always on the lookout, prowling.
Gary Wolfe is hardly the only one who questioned McDonald’s claims about wolves and predators not being impactful. I asked McDonald if he really believed what he said. “I don’t think predators are going to hurt our efforts in addressing CWD but I don’t think they are going to make a significant difference in stopping the spread of it. You’d have to have a pretty significant population of predators to have a significant reduction on populations of deer carrying CWD.”
McDonald has said that hunters are a better tool for trying to control CWD but it’s clear most hunters cannot discern an asymptomatic CWD-infected deer or elk from a healthy one.
Some 15 years ago and just months before he died tragically in an auto wreck, Tom Thorne, who had served as Wyoming chief wildlife veterinarian, acknowledged to Theo Stein of The Denver Post that cultural hatred of wolves trumped science. “Emotions against wolves are so strong that I’m not sure this potential benefit, which I agree might be there, would sway the opinions of many folks,” he said. “I think it would be a long, long time before people are used to wolves enough to admit they might be doing a bit of good.”
Is the civic dialogue and the public conversation about predators in Montana any more evolved? Bill Geer, president of the Montana Wildlife Federation, praised state wildlife managers for their bolstered surveillance and putting in motion an attempt to stop CWD before its foothold deepens. But he too encouraged McDonald and colleagues to reconsider their attitude toward predators.
“The outbreak [of CWD]…speaks to the benefit of having apex predators like wolves and mountain lions on the landscape. Wolves and mountain lions often preferentially kill compromised animals, and once a CWD infected animal starts to show signs of the disease, it will be easier to kill for wolves,” Geer wrote on Nov. 28, 2017. “That’s the way every effective predator hunts. That does not imply that CWD infected animals are not shedding the prions that spread the disease before they start to show symptoms. It does mean that predators could be a factor to help remove infected animals from the population. It’s important that these predators play their role in a functioning ecosystem.”
Few former civil servants in the world are more conversant on the topic of rural hostility toward predators than Norman Bishop. He spent 36 years with the National Park Service and played a vital role in Yellowstone’s drafting of an environmental impact statement on wolf reintroduction. The document drew upon the best available wolf science going back half a century, including studies of how the animals stalk prey.
Prior to wolves being brought back to Yellowstone, and afterward, Bishop gave more than 200 public presentations on the ecological role. He received many different forms of personal threats from people who refused to hear what he had to say and politicians even sought to have him fired for calling them out when they claimed wolves represented a pervasive threat to human safety.
In November, Bishop, who today is retired, attended the public meeting on CWD where McDonald asserted there is no evidence substantiating the value of predators. He is incredulous that McDonald made the claim. “Wolves are out there sweeping the landscape 365 days a year, rooting out sick animals. Why would you want to remove the best weapons you have? It makes no sense,” he told me. “What do the states have to lose by bringing predators into this fight which basically means just leaving them alone to do their jobs?”
One of the state officials who attended the recent Montana Fish and Wildlife Commission meeting told me, “Wolf advocates have been trying to get the commission to recognize the positive role of predators and make it an official part of the CWD strategy but there are folks pushing back who say they can’t handle anything that even remotely casts wolves in a positive light. People are reluctant to do it because they believe there would be a political downside.”
A political downside even worse than having Montana’s elk and mule herds decimated by CWD? I asked.
“What we are witnessing with wolves is a battle of modern scientific data against entrenched Old West dogma and we are in a time in which data doesn’t appear to matter to those who cling to dogma,” Bishop said. “It is disheartening to realize how the states have abandoned good sense.”
At a public event in Bozeman recently, before a crowded room, Bishop served up one of pioneering ecologist Aldo Leopold’s most famous quotes, lifted from Leopold’s book, A Sand County Alamanac. “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise.”
In their tome, Wolves on the Hunt, Mech, Smith and MacNulty note in field observation after field observation how difficult it is to be a predator like a wolf making a living with its mouth. The vast majority of predator attempts to take down large game animals are unsuccessful—by some estimates more than eight of every ten tries fail—and each one comes replete with the very real possibility that the wolf could get killed or maimed.
Survival of the fittest has a huge upside for those who care about elk and deer. “And so it goes, day after day, as wolves continue their rounds, ever searching for more vulnerable prey animals, chasing, missing, trying again and again, and eventually connecting,” the authors wrote. “The net result of all this sifting and selecting of prey over eons is that the prey gradually get faster, smarter, and more alert.”
Sadly, conservationists say, the U.S. Fish and Wildlife Service—the agency that is supposed to be a global leader in professional wildlife management—has been an accomplice in the CWD controversy. The agency continues to unnaturally feed thousands of wapiti at the National Elk Refuge under its command and yet the agency willfully is breaking its own mandates pertaining to wildlife health as noted by a panel of U.S. Circuit Court judges.
Second, Dorsey and Bishop note, it was the Fish and Wildlife Service which, in removing wolves from federal protection, handed over their management to Wyoming, knowing the very essence of recovering a species.
Never before in the history of the Endangered Species Act was an animal brought back only to, under state management, be immediately subjected to antiquated policies of re-eradication. If there were compelling reasons for artificially feeding wildlife, which is making the herds of Greater Yellowstone sicker, and for the gratuitous killing wolves, some of it might make sense. But none of it does, they note.
Today, akin to many fronts of U.S. environmental policy, discussions about the ecological niche of predators appears to be yet another example in which science and natural history are warped or ignored in favor of carrying out political agendas. In the case of wolves, are politicians refusing to accept reality because it cuts against the grain of myths they have helped to perpetuate and they are concerned they might lose votes from ecologically unenlightened constituents? If yes, what kind of wildlife management is it producing?
In the second part of this series, Tim Preso, a senior attorney with the environmental legal firm EarthJustice, noted that these are government agencies legitimizing their own known violations of laws, tenets and scientific truths in natural history that protect wildlife health. Instead, both federal and state agencies are violating the public trust doctrine they claim to uphold and spelled out in the North American Model of Wildlife Management.
“I don’t know that anything else exists with management policy in the Greater Yellowstone Ecosystem so blatantly contrary to the science, the law and common sense and involves a state that is so resistant to change,” he noted. Does that summation apply as equally to Montana and Idaho as to Wyoming? Preso doesn’t yet have an answer.