Arquivo da tag: Lobos

Monkeys and wolves forge alliance that resembles domestication done by humans (ZME Science)

In Ethiopia’s grasslands, huge herds of gelada monkeys might be in the process of domesticating wolves.

By Tibi Puiu, October 8, 2018

A) An Afroalpine rodent among geladas (Theropithecus gelada); B and C) Ethiopian wolves (Canis simensis) foraging for rodents among geladas; and D) an Ethiopian wolf successfully captures a rodent while among geladas. Credit: Journal of Mammalogy.
A) An Afroalpine rodent among geladas (Theropithecus gelada); B and C) Ethiopian wolves (Canis simensis) foraging for rodents among geladas; and D) an Ethiopian wolf successfully captures a rodent while among geladas. Credit: Journal of Mammalogy.

In the grasslands of Ethiopia, scientists were amazed to find a striking example of inter-species collaboration. Ethiopian wolves were seen casually strolling among herds of gelada monkeys, which you would expect to flee out of the way of such a predator. But it seems like the monkeys tolerate the wolves in their presence and are not frightened by them. The wolves, on the other hand, ignore the geladas’ potential as meals, preferring to linger around the herd because it helps them catch more rodents. This odd relationship resembles the ancient domestication of dogs or cats by humans, some researchers say.

Live and let live

Gelada monkeys (Theropithecus gelada) look a lot like baboons. These primates are known to live in close-knit family groups, but can also live as part of shockingly vast communities consisting of hundreds of individuals. They live peacefully even in the most numerous communities, a relatively rare achievement in the wilds of Africa.

Geladas are graminivores, meaning their diet consists of 90% grass. Essentially, they’re the only living primates that subsist almost entirely on grass, a trait more commonly seen in ungulates like deer and cattle.

While the primates congregate in huge herds, munching on grass for hours upon hours, the shrewd (and endangered) Ethiopian wolf (Canis Simensis) mingles with the geladas. Usually, the wolves travel in zig-zag, sprinting when they sense prey is within their grasp. But, around the geladas, the wolves roam casually, being careful not to startle the herd.

Researchers at Dartmouth College observed the dynamics between the species for a new study. They conclude that the Ethiopian wolf is not interested in geladas for food, although they have no qualms hunting juvenile sheep and goat. The monkeys seem to know this, as they don’t seem to feel threatened in the predators’ presence. But why is that?

After following Ethiopian wolves for 17 days, the researchers found that those individuals which hunted rodents within a gelada herd were successful 67% of the time, compared to a success rate of only 25% when they prowled on their own. The findings were reported in the Journal of Mammalogy.

“For Ethiopian wolves, establishing proximity to geladas as foraging commensals could be an adaptive strategy to elevate foraging success. The novel dynamics documented here shed light on the ecological circumstances that contribute to the stability of mixed groups of predators and potential prey,” wrote the authors of the new study.

For now, it’s not clear what makes the wolves more successful when hunting within gelada groups. The monkeys might be flushing out rodents from their burrows due to their insistent grazing, but that’s just an unverified hypothesis at the moment. Alternatively, the monkeys might be providing cover for the wolves, distracting the rodents from the dangerous predator.

The Ethiopian Wolf -- also known as ‘ky kebero’, which means red jackal -- is one of the rarest and most endangered of all canids. Credit: Wikimedia Commons.
The Ethiopian Wolf — also known as ‘ky kebero’, which means red jackal — is one of the rarest and most endangered of all canids. Credit: Wikimedia Commons.

Sometimes, a wolf will attack a gelada young. During one instance when this happened, the other monkeys in the herd quickly attacked the wolf, forcing it to drop the infant. After the wolf was driven away, it was never allowed in the midst of the herd again. Other individuals seem to understand this dynamic very well and will resist the temptation of grabbing a quick gelada meal in favor of the prospect of better dividends in the long run.

The researchers say that the Ethiopian wolf might be hanging around other species, such as cattle, to hunt more rodents. It’s also possible other predator species may be doing something similar without us finding out about it yet.

What’s intriguing is that the gradual toleration between the two species is very similar to the domestication process performed by humans on dogs. The first wolves began to be domesticated by humans sometime between 40,000 and 11,000 years ago, but the details pertaining to how this happened are not clear. According to one hypothesis, wolves started hanging around humans, who would leave large carcasses behind them after each big hunt. Gradually, the two species became more accustomed to one another. Later, wolves may have helped humans on the hunt, cementing the relationship between the two.

Could the same thing be happening in Ethiopia’s grasslands? Given a couple thousand of years, could we see geladas with wolves as pets? That would be quite the sight — but it’s rather unlikely. The monkeys don’t seem to derive any benefit from tolerating the wolves in their presence, and without a two-way value exchange between the two species, domestication won’t likely happen.

What’s more, the Ethiopian wolf might become extinct soon before there’s any reasonable time for domestication to play out. Researchers estimate that there are only 450 adult Ethiopian wolves left in the wild. Continuous loss of habitat due to high-altitude subsistence agriculture represents the major current threat to the Ethiopian wolf.

Wolves and the Ecology of Fear (Quest)

Video Story by  for  on Mar 06, 2014


Does “the big bad wolf” play an important role in the modern-day food web? In this video we journey to Washington State’s Cascade Mountains, where the return of wolves could have a profound impact on a vast wilderness area. We meet up with biologist Aaron Wirsing to explore why wolves and other top predators are needed for diverse ecosystems to flourish. Using a simple video camera (a “deer-cam”) Wirsing is gaining a unique perspective on predator/prey relationships and changing the way we think about wolves.

Wolves in the Crosshairs:  Q&A with conservationist, Fred Koontz

Fred Koontz

Dr. Fred Koontz

Gray wolves are in the crosshairs of a heated conservation debate, with the federal government trying to strip all protections for them in the continental U.S. Dr. Fred Koontz, vice president of field conservation at Woodland Park Zoo, Seattle, has worked in conservation for three decades and has studied the wolf issue. We talked with Dr. Koontz about the future of wolves in the U.S. and the role they play in maintaining healthy ecosystems.

Wolves may be the most polarizing animal in North America, more so than other large carnivores like cougars or grizzly bears. Why?
The gray wolf is one of the world’s most adaptable and widely distributed mammals, ranging over much of Asia, Europe, and North America. Wolves, the size of a German shepherd, are pack-hunting predators that sometimes kill livestock. Combined with wolves’ nocturnal behavior and haunting howling, this has resulted in a long history of conflict with people, especially as human numbers have increased exponentially in recent centuries and agricultural lands expanded into wolf habitat. There are, however, very few documented cases of wolves attacking people, but the rare times it’s happened it’s been sensationalized and blown out of proportion.

How have your perceptions or understanding of wolves changed over the years?
At an early age, my mother read with much theatrical expression “Little Red Riding Hood,” which, like many children, left me fearing the “big bad wolf.” This negative image was reinforced with similar wolf-themed horror movies that I ashamedly spent far too much time watching in my youth. Only when I studied ecology and animal behavior in college and as a wildlife professional did I see a different image of the wolf. Wolves are important regulators of prey numbers and behavior, and as such, influence a web of ecological interactions that enrich biological diversity. I learned also that among many adaptive traits enabling their evolutionary success, wolves have a rich social life and extraordinary set of communication behaviors. The more I learned, the more fascinated I became in understanding how wolves and people might live together for their mutual benefit.

Gray wolves have been taken off the federal endangered species list in some states, such as Idaho, Wyoming, and Montana. And a recent federal proposal would strip all gray wolves in the continental U.S. of their federal protection. How did this come to be? What kind of politics are at play?


Gray wolves can come in an assortment of colors, such as these all-white wolves. Photo courtesy of Ryan Hawk, Woodland Park Zoo, Seattle.

Under the Endangered Species Act, the U.S. Fish and Wildlife Service (USFWS) in 1974 first listed gray wolves as endangered in the lower 48 states. Now they propose to remove them from the ESA list. This idea follows from three decades of actions undertaken by federal, state, and local partners that resulted in population recovery and delisting in 2011 of wolves living in the western Great Lakes states and northern Rockies. With about 6,000 wolves residing in these two recovery areas, USFWS believes that the gray wolf population in general is well established and stable enough to warrant delisting. Many state wildlife officials welcome the move as they are eager to take back the management authority for animals within their political borders.

However, many conservation scientists and wolf advocates believe that more time on the endangered species list — and [under] federal protection — would allow wolves a greater opportunity to reclaim more of their former territory and grow the number of their populations. This is important because, despite wolf recovery success in the Great Lakes states and Rocky Mountains, there is still a lot of their former range not yet occupied. Expanded range and more populations, in turn, will provide greater species resiliency to unexpected environmental disruptions like climate change and emerging diseases and also improve long-term wolf survival in the U.S.

An independent review panel recently found that the federal government used uncertain science when it proposed removing the gray wolf from the endangered species list across the lower 48 states. What could that mean for the future of wolves?
This is important because under Endangered Species Act law the U.S. Fish and Wildlife Service is obligated to use the best available science. The Service claimed that new genetic research indicated that wolves living in the eastern U.S. were actually a different species, and thus should not be considered as part of the original listing or part of the historic range. The expert panel said the genetic research was uncertain and based largely on one paper. The panel’s report has reopened the debate about delisting gray wolves, and I suspect it will extend the time wolves remain listed. The final decision on delisting is yet to be determined — public comment isencouraged. [Note: deadline is March 27, 2014]

In the long run, the debate about delisting wolves invites larger questions like, what constitutes full recovery of any endangered species, and does the legal framework of the ESA reflect current conservation science and principles of sustainable living? Most importantly, there needs to be agreement at the onset about the ultimate purpose of recovery — is it simply species survival or restoring ecological function? There are no easy answers.

Mule Deer Lauren Sobkoviak

Mule Deer photo courtesy of Lauren Sobkoviak.

Is it possible for wolves and humans to coexist? What needs to change for that to happen?
I think that wolves and humans ultimately will coexist by sharing land in two key places — protected areas and rural areas managed for the benefit of people and wildlife, for example, park buffer lands, multiple-use public lands, and designated wildlife corridors. For the reconciliation between wolves and humans to prove fully successful, we will first need a broader understanding of the role that apex predators play in creating healthy ecosystems and why healthy ecosystems are needed by people. In other words, there must be a broader understanding of why saving wolves is essential to sustainable living. Greater public will to save wolves will result in increased public spending needed to conduct science and carry out sound management actions. For example, we need more research on improving ranching practices to minimize wolf predation of livestock, and insurance programs that compensate ranchers for unavoidable losses. There is already good evidence from pilot efforts that such research and management programs are possible — and that they work!

Why should people care about the fate of wolves?
The fate of wolves is tied directly to the greatest challenge facing humankind this century —  sustainable living! With more than seven billion people consuming resources at an accelerating pace, this generation of world citizens must transform our societies to sustainable ones. We must, among other things, protect a wide variety of animal and plant species — scientists call this “biodiversity.” Many conservation scientists believe that apex predators (animals at the top of the food chain), like wolves, are necessary to maintain habitats rich in life. In turn, high levels of biodiversity bring many direct benefits to people — everything from providing food and fiber to protecting water supplies and enriching recreation.

Scientist 1

Biologist Aaron Wirsing for the University of Washington (right) and graduate student Justin Dellinger (left) radio collar deer with video cameras in order to better understand predator-prey dynamics. Photo courtesy of Greg Davis.

Understanding the links between apex predators and biodiversity is a growing area of research for scientists like Aaron Wirsing of the University of Washington. Since 2008, wolves have been returning to Washington and have reestablished populations in the U.S. northern Rockies. This has provided a unique research opportunity for Wirsing and other scientists. For example, deer populations in Washington have likely over-browsed plants for decades in the absence of gray wolves. One consequence of deer eating trees along streambeds is less habitat for birds, and streams that are more likely to harbor fewer cold-water fish like trout because they are filled with sediments from soil erosion and overheated because of lack of shade. With wolves back in the state, Wirsing is leading a study to document how wolves are changing mule and white-tail deer populations, which in turn affects forest landscapes.

Why do you care about wolves?
I care about wolves because as apex predators they contribute significantly to enriching biodiversity needed by people for sustainable living. I also care about wolves because I admire them! Wolves are amazing for many reasons, but I am especially fascinated by their complex social behavior and adaptable lifestyles, two traits that they share with humans. Also, one of the most important reasons I care is that wild wolves in the U.S. are a symbolic way of keeping our American heritage of wilderness alive.

Additional Resources/Links:

U.S. Plan to Lift Wolf Protections in Doubt After Experts Question Science (Science)

8 February 2014 10:45 am

Canis lupus

Wikimedia/USFWS. Canis lupus

The ongoing battle over a proposal to lift U.S. government protections for the gray wolf (Canis lupus) across the lower 48 states isn’t likely to end quickly. An independent, peer-review panel yesterday gave a thumbs-down to the U.S. Fish and Wildlife Service’s (USFWS’s) plan to delist the wolf. Although not required to reach a consensus, the four researchers on the panel were unanimous in their opinion that the proposal “does not currently represent the ‘best available science.’ ”

“It’s stunning to see a pronouncement like this—that the proposal is not scientifically sound,” says Michael Nelson, an ecologist at Oregon State University, Corvallis, who was not one of the reviewers. Many commentators regard it as a major setback for USFWS, which stumbled last year in a previous attempt to get the science behind its proposal reviewed.

USFWS first released its plan for removing the gray wolf from the endangered species list in June 2013. The plan also called for adding the Mexican gray wolf, a subspecies that inhabits the southwest, to the protected list. At the time, there were approximately 6000 wolves in some Western and upper midwestern states; federal protections were removed from the gray wolf in six of those states in 2011. More than 1 million people have commented on the plan. But regulations also require that the agency invite researchers outside of the agency to assess the proposal’s scientific merit.

At its core, the USFWS proposal relies on a monograph written by its own scientists. They asserted that a different (and controversial) species, the eastern wolf (Canis lupus lycaon) and not the gray wolf, had inhabited the Midwest and Northeast. If correct, then the agency would not need to restore the gray wolf population in 22 eastern states, where gray wolves are no longer found.

But the four reviewers, which included specialists on wolf genetics, disagreed with USFWS’s idea of a separate eastern wolf, stating that the notion “was not universally accepted and that the issue was ‘not settled’ ”—an opinion shared by other researchers. “The designation of an ‘eastern wolf’ is not well-supported,” says Carlos Carroll, a conservation biologist at the Klamath Center for Conservation Research in Orleans, California, who was not a member of the review panel.

Overall, the agency’s “driving goal seemed to be to identify the eastern wolf as a separate species, and to use that taxonomic revision to delist the gray wolf,” says Robert Wayne, a conservationist geneticist at the University of California (UC), Los Angeles, and one of the reviewers. If that were to happen, he says, it would be the first time that a species was removed from the federal endangered species list via taxonomy. “It should happen when a species is fully recovered,” Wayne says, “and the gray wolf is not. It’s not in any of those 22 eastern states—that’s why it’s endangered there.”

The panel’s statements will make it difficult, outside observers say, for USFWS to move forward with its proposal. The Endangered Species Act requires that decisions to remove a species from federal protection be based on the “best available science.”  And because the reviewers have concluded this is not the case, “you’ve got to think that the [service] must go back to the drawing board,” says Andrew Wetzler, director of land and wildlife programs for the Natural Resources Defense Council in Chicago, Illinois, an organization that advocates for continued federal protections for the wolf.

Gray wolves were exterminated across most of the lower 48 states in the last century. They were placed on the endangered species list in 1975, and successfully reintroduced into Yellowstone National Park and Idaho in 1995. Gray wolves also made a comeback in the Great Lakes region, where they now can be legally hunted. Idaho, Wyoming, and Montana also have wolf hunting and trapping seasons. Smaller gray wolf populations that aren’t legally hunted are found in Washington and Oregon.

The agency’s reaction to the peer-review comments has been somewhat muted. In a press statement, it thanked the National Center for Ecological Analysis and Synthesis at UC Santa Barbara for conducting the review. USFWS Director Dan Ashe noted that “[p]eer review is an important step in our efforts to assure that the final decision on our proposal to delist the wolf is based on the best available scientific and technical information,” and that the panel’s comments will be incorporated in the ongoing process of reaching a decision on the fate of the gray wolves.

The peer-review report is now available online. USFWS will reopen the public comment period on its delisting proporal on 10 February, and will accept comments through 27 March.

Age-Old ‘Man v. Wolf’ Battles Are Back In Europe (Worldcrunch)

Julie Farrar (2014-01-11) 

Article illustrative image

Iberian wolf in Lugo, Spain

“Wolves are not killed because they are grey, but because they eat sheep.”  (Russian proverb)

Who’s afraid of the Big, Bad Wolf? Well, as it turns out, more than just the shepherds whose flocks get devoured. In European culture, there is a deep-rooted negative image of the wolf, based on fear of attacks on humans — thanks to well-known children’s stories — combined with the loss of livestock, and therefore livelihood, to wolf depredation.

And over the past decade, as the number of members of the species has increased, humans are the ones on the attack.

In the central Italian city of Terni, a she-wolf was shot dead. This comes as in the coastal forest of Tuscany, eight wolves have been killed since November — three in the last week alone. In these most recent kills, two of which were wolf-dog hybrids, the animals had been tied up on a city street where they were beaten, shot and left abandoned as acts of “demonstrative warning,” according to La Stampa.

Giacomo Bottinelli of the Italian animal rights group LAV blamed sheep farmers and lax hunting regulations that he says “guarantee the impunity of dangerous criminals.”

Meanwhile, in Tamins, Switzerland, a wolf was found dead this week, and it was determined that it had been shot two weeks earlier and left to succumb to a slow and painful death, reports 24 Heures. “This situation surprised us completely, even if we knew the local population was concerned by the presence of the wolf pack in the area,” said State Councilor Mario Cavigelli. “Completely informing the population is our top priority. Wolves are not dangerous as long as we don’t feed them.”

Experts note that there are solutions to keep the animals at bay, e.g. the use of rubber bullets, flashing lights and even the presence of sheepdogs. It’s true that as predation grows, an open debate must take place — but funds are lacking and the shepherds need help.

Pets in the middle

In Germany, as elsewhere, it was believed that the species had been hunted to extinction more than a century ago. But over the past decade, wolves have returned, migrating back from Eastern Europe and reigniting ancient fears. German weekly Der Spiegel reports that researchers at the Senckenberg Society for Natural Research proved that livestock accounts for less than 1% of wolves’ diets.

The resurgence of the animals has caused anger amongst farmers, who declare that the wolves are not just eating their sheep and other livestock, but household pets as well.

“We’re not against wolves, but we want them to stay on government-owned lands. When they leave these territories, we want to be able to shoot them,” said Lutz-Uwe Kahn, of the Brandenburg Farmers Alliance, quoted in Der Tagesspiegel.

There is the fear that the wolves will attack humans but, as Werner Freund proved to VICE magazine, it is entirely possible to co-habitate with them. Freund, a former marine, has been living with wild wolves in Merzig, a small town near the French border, for the past 30 years. He firmly believes that wolves only attack when cornered, and that fairy tales have brought up to believe they are to be feared. “If we say that wolves shouldn’t live here,” he continues, “then we have no right to complain about the killing of elephants in Africa for ivory.”

While Freund’s view is certainly atypical, as very few people in the world have had similar experiences with the species as he has, Germany is not the only country that is experiencing a comeback from the creatures: After an absence of 70 years, they’re back in Spain’s Guadarrama mountains, just 65 kilometers from Madrid.

Over the past two months, writes The Guardian, around 100 sheep and cattle have been killed near Buitrago, in the northern foothills of the Guadarrama mountains, says Juan Carlos Blanco, a wolf specialist and adviser to the Spanish environment ministry.

“Guadarrama can support two, even three, packs. We think there are now six packs within 100 kilometers of Madrid. When they arrive in a new area the shepherds don’t know what to do. Then they find ways to protect their flocks with dogs or fences. It’s a natural event, and the wolf will not go away now,” he says.

Blanco notes that even if hunters exterminate one pack, others will take its place. “Wolves, he said, “are very adaptable and resilient.”

Domestication of Dogs May Have Elaborated On a Pre-Existing Capacity of Wolves to Learn from Humans (Science Daily)

Dec. 3, 2013 — Wolves can learn from observing humans and pack members where food is hidden and recognize when humans only pretend to hide food, reports a study for the first time in the open-access journal Frontiers in Psychology. These findings imply that when our ancestors started to domesticate dogs, they could have built on a pre-existing ability of wolves to learn from others, not necessarily pack members.

The researchers conclude that the ability to learn from other species, including humans, is not unique to dogs but was already present in their wolf ancestors. Prehistoric humans and the ancestors of dogs could build on this ability to better coordinate their actions. (Credit: Wolf Science Center)

A paper published recently in the journalScience suggested that humans domesticated dogs about 18 thousand years ago, possibly from a European population of grey wolves that is now extinct. But it remains unknown how much the ability of dogs to communicate with people derives from pre-existing social skills of their wolf ancestors, rather than from novel traits that arose during domestication.

In a recent study, Friederike Range and Zsófia Virányi from the Messerli Research Institute at the University of Veterinary Medicine Vienna investigated if wolves and dogs can observe a familiar “demonstrator” — a human or a specially trained dog — to learn where to look for food within a meadow. The subjects were 11 North American grey wolves and 14 mutts, all between 5 and 7 months old, born in captivity, bottle-fed, and hand-raised in packs at the Wolf Science Center of Game Park Ernstbrunn, Austria.

The wolves and dogs were two to four times more likely to find the snack after watching a human or dog demonstrator hide it, and this implies that they had learnt from the demonstration instead of only relying on their sense of smell. Moreover, they rarely looked for the food when the human demonstrator had only pretended to hide it, and this proves that they had watched very carefully.

The wolves were less likely to follow dog demonstrators to hidden food. This does not necessarily mean that they were not paying attention to dog demonstrators: on the contrary, the wolves may have been perceptive enough to notice that the demonstrator dogs did not find the food reward particularly tasty themselves, and so simply did not bother to look for it.

The researchers conclude that the ability to learn from other species, including humans, is not unique to dogs but was already present in their wolf ancestors. Prehistoric humans and the ancestors of dogs could build on this ability to better coordinate their actions.

Journal Reference:

  1. Friederike Range and Zsófia Virányi. Social learning from humans or conspecifics: differences and similarities between wolves and dogsFrontiers In Science, 2013 DOI:10.3389/fpsyg.2013.00868