Do wolves, cougars help curb diseases?

copyrighted Hayden wolf walking

April 2, 2014 4:30 am

The New West / By Todd Wilkinson

“Predators are bad for wildlife.” How often have Americans heard this refrain in public forums?

Pervasive as a belief in rural Western culture, it drives political discourse. It also is part of a nonstop feedback loop of social reinforcement, rife in barber shops, ammo stores, saloons, coffee klatches and outfitter camps.

But does it withstand scientific scrutiny? Do predators such as wolves and cougars “devastate” wildlife or do they help keep public game herds healthier?

Predator experts and others specializing in wildlife conservation medicine say it’s an important consideration when thinking about protocols for managing zoonotic diseases in the Greater Yellowstone Ecosystem.

I contacted biologist L. David Mech, one of the world’s foremost wolf authorities. He has written or contributed to hundreds of peer-reviewed scientific papers on wolves and prey.

“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 began. “There’s so much documented field data behind it.”

All the things humans treasure about every wild prey species — their physiology, agility and resilience — are reflections of the predators that made them adapt and evolve over eons.

Keeping domestic livestock healthy and fat often involves huge doses of antibiotics and, in some cases, growth hormones. Not so for free-ranging wildlife, especially wildlife not subjected to unnatural animal husbandry practices, such as artificially nourishing wild elk at crowded feedgrounds.

Wildlife professionals know such conditions elevate animal susceptibility to deadly pathogens like brucellosis, tuberculosis and chronic wasting disease, threatening ecological well-being.

Mech made a fascinating point: 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.”

In 2003, Denver Post reporter Theo Stein interviewed scientists about CWD spreading though deer and elk in Colorado. Dr. Valerius Geist, who paradoxically has become a darling of anti-wolfers, 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,” he said. “They will remove infected individuals and clean up carcasses that could transmit the disease.”

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.”

Wolves aren’t alone. In a 2009 study titled “Mountain lions prey selectively on prion-infected mule deer,” researchers in Colorado discovered that “adult mule deer killed by mountain lions were more likely to be prion-infected than were deer killed more randomly … suggesting that mountain lions were selecting for infected individuals when they targeted adult deer.”

Researchers said, “Other studies indicate that predators like wolves and coyotes select prey disproportionately if they appear impaired by malnutrition, age or disease.”

In another study researcher N. Thompson Hobbs examined the potential impact of wolves on CWD-infected elk in Rocky Mountain National Park, where lobos are now absent.

Wolves, he found, could reduce average life spans of infected elk and therefore limit the amount of time infectious animals could spread disease to others.

“We suggest that as CWD distribution and wolf range overlap in the future, wolf predation may suppress disease emergence or limit prevalence,” Hobbs said.
Wyoming doesn’t accept this scientific reality. In Jackson Hole, where unnatural feeding of wapiti on the National Elk Refuge is contributing to persistent brucellosis infection and putting migrating elk at high CWD risk, wolves are killed under the ironic guise of “keeping elk herds healthy.”

In Wyoming’s “predator zone” which encompasses many of the state’s 22 elk feedgrounds, wolves can be killed at any time of day year round.

Are Wyoming, Idaho and Montana spending millions in tax dollars to eliminate the natural allies that help keep wildlife diseases such as brucellosis and CWD in check? 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.”

Todd Wilkinson’s column appears every week in the News&Guide. He is author of “Last Stand: Ted Turner’s Quest to Save a Troubled Planet.”

Eight things you should know about the deadly Ebola virus

By Joyce Teo

An outbreak of Ebola virus disease (EVD) in Guinea, West Africa has killed 78 people, prompting travel alerts and putting the spotlight back on one of the world’s deadliest diseases.

Cases have been confirmed in several locations in Guinea, including the capital Conakry.

This is in contrast to previous outbreaks, which were much more geographically contained. They also occurred in more remote places.

Here’s what you should know about the viral haemorrhagic fever.

1. The World Health Organisation (WHO) calls it “one of the most virulent diseases known to humankind”.

2. It can kill up to 90 per cent of the people who are infected with it.

There has been more than 1,800 Ebola cases, with nearly 1,300 deaths.

3. Outbreaks occur primarily in remote villages in Central and West Africa, near tropical rainforests.

4. The virus first appeared in 1976 in Nzara, Sudan and in Yambuku, Democratic Republic of the Congo.

It took its name from the Ebola River, which was near the village in Yambuku where the outbreak occurred.

4. Ebola can be caught from both humans and animals.

It is transmitted through close contact with blood, secretions or other bodily fluids. Fruit bats are considered to be the natural host of the Ebola virus.

5. It spreads quickly through human-to-human transmission, as family and friends care for infected people.

Health-care workers have frequently been infected while treating Ebola patients.

6. Symptoms can appear from two to 21 days after exposure. Early symptoms such as rashes and red eyes are common, making it hard to diagnose in the early stages.

7. The virus spreads in the blood and paralyses the immune system.

Ebola is often characterised by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat.

This is followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding such as from the nose or via a person’s urine.

8. There is no specific treatment or vaccine available for people or animals.

Sources: WHO, Médecins Sans Frontières


As Predators Vanish, Ecosystems Thrown Off Balance: Scientists

‘Ironically, they are vanishing just as we are learning about their important ecological effects’

  – Sarah Lazare, staff writer

African Leopard in Etosha National Park, Namibia (Photo: Patrick Giraud / Wikimedia Creative Commons)A steep decline in large predators is threatening endangered species and disrupting ecosystems from the tropic to the arctic, scientists warn.

Over 75 percent of the 31 large carnivore species—including lions, dingoes, wolves, otters, and bears—face shrinking numbers, according to a Friday report in the journal Science. Of these, 17 species now live in less than half of the ranges they previously occupied.

Human extermination, as well as a reduction in habitat and prey, are creating “hotspots” of decline, found the scientists—who reviewed studies and singled out the ecological effects of 7 large predators facing steep decline. While southeast Asia, southern and eastern Africa and the Amazon face dwindling numbers, much of western Europe and the eastern United States have already exterminated the huge bulk of their large predators.

“Globally, we are losing our large carnivores,” said William Ripple, lead author of the paper and a professor in the Department of Forest Ecosystems and Society at Oregon State University. “Many of them are endangered,” he said. “Their ranges are collapsing. Many of these animals are at risk of extinction, either locally or globally. And, ironically, they are vanishing just as we are learning about their important ecological effects.”

This decline is throwing off the balance of ecosystems across the globe, say the scientists.

The decrease of cougars and wolves in national parks in North America, including Yellowstone, leads “to an increase in browsing animals such as deer and elk. More browsing disrupts vegetation, shifts birds and small mammals and changes other parts of the ecosystem in a widespread cascade of impacts,” according to a summary of the findings.

In some areas of Africa, a plummet in lion and leopard populations has led to an increase in olive baboons, which take a toll on human crops and livestock, the scientists find.

The scientists—who hail from Australia, Italy, Sweden, and the United States—document similar effects across the globe.

“Human tolerance of these species is a major issue for conservation,” Ripple said. “We say these animals have an intrinsic right to exist, but they are also providing economic and ecological services that people value.”

“Nature is highly interconnected.”

Wolf Hunters Prefer an Imbalance of Nature

First, a reminder to hunters who might happen upon this blog: please don’t bother commenting in support of your sport. Pro-hunting comments don’t get posted here. There are plenty of other forums for that sort of thing. Though your arguments may be “heartfelt” and well thought out, all pro-kill comments end up in the round file. Readers here have heard you sportsmen’s rationalizations ad nauseum and instinctively know the truth about hunting. Anyone wanting to hear hunter rationalizations can visit any number of sites dedicated to the disemination of hunter propaganda–this is not one of them.


Now back to today’s sermon:

In a recent discussion on wildlife issues with some longtime friends, I felt a little out of place to learn they were all against the reintroduction of wolves to places like Idaho, Montana and Wyoming. No, they weren’t a group of hunters selfishly seeking authority over nonhuman life; these good folks were understandably upset because the wolves are being killed in horrible ways, ever since their removal from the federal endangered species list left them at the mercy of state game department policy makers. While I share their outrage and the urge to end the suffering of wolves, I have to argue that at least the ones “that got away” will go on to fill a gap in biodiversity.

The point of recovering endangered species should be to bring back and/or protect enough diversity to allow nature to function apart from human intervention. The presence of predators like wolves can help to restore a sense of natural order and nullify the claims by hunters that their sport is necessary to keep ungulate populations in check.

Wolves in Yellowstone have been keeping elk on the move enough to allow willows to thrive once again in places like the Lamar Valley. Newly emerging willow thickets in turn provide food and shelter for an array of species, from beavers to songbirds. The loss of each thread of biodiversity brings us one step closer to a mass extinction spasm that would wreak more destruction and animal suffering than the Earth has seen in some 50 million years.

Hunters want their cake and eat it too. Out of one side of their mouth they declare that there are too many elk and that they do the animals a favor by killing them to prevent overgrazing. Yet when wolves spread out and successfully reclaim some of their former territories, hunters resent the competition and call for every brutal tactic imaginable to drive wolves back into the shadows, thereby restoring the imbalance that hunters depend on to justify their exploits.

Now more than ever we need to counter the hunter agenda at every turn, for the sake of a functioning planet. It’s high time to put an end to the notion that wildlife are “property” of the states, to be “managed” as they see fit. The animals of the Earth are autonomous, each having a necessary role in nature. Only human arrogance would suppose it any other way.


Nature Doesn’t Need a Manager

When I started into college, I wanted to go into wildlife management. 

Okay, I know what you’re saying to yourself: “Wait…what?” “WTF?”  “Wildlife doesn’t need a manager!” “What the hell was he thinking?!”

Clearly, I didn’t know what I was getting into. I knew I loved animals and wanted to work around wildlife, but what I didn’t realize was that about the only work in that field was in some game department promoting hunting, or in the vile Wildlife “Services” department, killing off animals by the droves in horrible ways.                                                         

I had enrolled in a small, rural college where the same teacher taught every class in the wildlife curriculum. In an obvious plug for the local logging industry, he started off each class (no matter which course he was teaching) with the mantra, “Clear cuts are good for wildlife,” at which point I would raise my hand and ask, “What about wolves or wolverine or grizzly bears who prefer wilderness and try to avoid people whenever possible?” To that he would rephrase his spiel and say, “Clear cuts are good for deer.” 

It didn’t take long before I realized that wildlife “management” had an agenda, a higher purpose—to serve the hunting industry. Not, as I had imagined, to serve wildlife or to promote the balance of nature. No, quite the opposite, in fact.

Although it had been well established by then that the way to ensure healthy populations of ungulates was to maintain healthy populations of natural predators, “game” managers continued to make the same mistake that Aldo Leopold, known as the father of wildlife management, made in 1926. In a Sand County Almanac, Leopold reveals a regrettable experience that many people still haven’t learned from:

“We saw what we thought was a doe fording the torrent, her breast awash in white water. When she climbed the bank toward us and shook out her tail, we realized our error: it was a wolf. A half-dozen others, evidently grown pups, sprang from the willows and all joined in a welcoming melee of wagging tails and playful maulings. What was literally a pile of wolves writhed and tumbled in the center of an open flat at the foot of our rimrock.

“In those days we had never heard of passing up a chance to kill a wolf. In a second we were pumping lead into the pack, but with more excitement than accuracy…When our rifles were empty, the old wolf was down, and a pup was dragging a leg into impassable side-rocks. We reached the old wolf in time to watch a fierce green fire dying in her eyes. I realized then, and have known ever since, that there was something known only to her and to the mountain. I was young then, and full of trigger-itch; I thought that because fewer wolves meant more deer, that no wolves would mean hunters’ paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view.”

Unfortunately, Aldo Leopold’s eventual understanding of wolves’ necessary place in a healthy ecosystem came too late for at least one New Mexico pack. Judging by the vehemence with which today’s hunters are targeting wolves, it’s plain to see that wildlife management still hasn’t come very far in its grasp of nature’s mechanisms.

Richard Leaky, author of The Sixth Extinction, points to the folly of trying to manage wildlife, “It is far better to understand and accept the world of nature in its infinite variety and its infinitely complex processes, acknowledging the near futility of attempts to control them, than to imagine through ignorance that it is possible to do so.”     

Hyder wolf photo
Copyright, Jim Robertson