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The wolves affect the population of the elk because they mainly eat elk. In the populations presentation it was discovered that, "Researchers have also determined that wolves, in the recent absence of hard winters, are now the primary reason for elk mortality." the wolves are hunting the elk. When the wolves started to hunt the elk they, " the elk pushed the limits of Yellowstone's carrying capacity, and they didn't move around much in the winter-browsing heavily on young willow, aspen and cottonwood plants. " The elk had been over grazing the willow killing them off. when the wolves came back and started to kill the elk, the elk didn't have time to graze on the young trees. So with no elk grazing on them their populations began to grow.

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On a quiet spring morning, a resounding "Slap!" reverberates through the air above a remote stream leading to Lake Yellowstone. Over much of the past century, it has been a rarely heard noise in the soundscape that is Yellowstone National Park, but today is growing more common-the sound of a beaver slapping its tail on the water as a warning to other beavers.

When the grey wolf was reintroduced into the Greater Yellowstone Ecosystem in 1995, there was only one beaver colony in the park, said Doug Smith, a wildlife biologist in charge of the Yellowstone Wolf Project.

Today, the park is home to nine beaver colonies, with the promise of more to come, as the reintroduction of wolves continues to astonish biologists with a ripple of direct and indirect consequences throughout the ecosystem.

A flourishing beaver population is just one of those consequences, said Smith.

A Yellowstone Beaver's Tale of Elk

What happened, said Smith, is that the presence of wolves triggered a still-unfolding cascade effect among animals and plants-one that will take decades of research to understand.

"It is like kicking a pebble down a mountain slope where conditions were just right that a falling pebble could trigger an avalanche of change," Smith mused.

So how did this avalanche of change work out for the beaver?

To answer that, you have to go back to the 1930s, when the wolf was killed off in Yellowstone. Even though Yellowstone elk were still preyed upon by black and grizzly bears, cougars and, to a lesser extent, coyotes, the absence of wolves took a huge amount of predatory pressure off the elk, said Smith. As a result, elk populations did very well-perhaps too well. Two things happened: the elk pushed the limits of Yellowstone's carrying capacity, and they didn't move around much in the winter-browsing heavily on young willow, aspen and cottonwood plants. That was tough for beaver, who need willows to survive in winter.

Healthier Willow Stands in Yellowstone

This created a counterintuitive situation. Back in 1968, said Smith, when the elk population was about a third what it is today, the willow stands along streams were in bad shape. Today, with three times as many elk, willow stands are robust. Why? Because the predatory pressure from wolves keeps elk on the move, so they don't have time to intensely browse the willow.

Indeed, a research project headed by the U.S. Geological Survey in Fort Collins found that the combination of intense elk browsing on willows and simulated beaver cuttings produced stunted willow stands. Conversely, simulated beaver cutting without elk browsing produced verdant, healthy stands of willow. In the three-year experiment, willow stem biomass was 10 times greater on unbrowsed plants than on browsed plants. Unbrowsed plants recovered 84 percent of their pre-cut biomass after only two growing seasons, whereas browsed plants recovered only 6 percent.

With elk on the move during the winter, willow stands recovered from intense browsing, and beaver rediscovered an abundant food source that hadn't been there earlier.

As the beavers spread and built new dams and ponds, the cascade effect continued, said Smith. Beaver dams have multiple effects on stream hydrology. They even out the seasonal pulses of runoff; store water for recharging the water table; and provide cold, shaded water for fish, while the now robust willow stands provide habitat for songbirds.

"What we're finding is that ecosystems are incredibly complex," he said. In addition to wolves changing the feeding habits of elk, the rebound of the beaver in Yellowstone may also have been affected by the 1988 Yellowstone fires, the ongoing drought, warmer and drier winters and other factors yet to be discovered, Smith said.

Yellowstone Wolf Trophic Cascade

Biologists are often faced with the grim task of documenting the cascade effects of what happens when a species is removed from an ecosystem, by local extirpation or even extinction. In Yellowstone, biologists have the rare, almost unique, opportunity to document what happens when an ecosystem becomes whole again, what happens when a key species is added back into the ecosystem equation.

"In the entire scientific literature, there are only five or six comparable circumstances," Smith said. "What we're seeing now is a feeding frenzy of scientific research."

Scott Creel, an ecology professor at Montana State University, is hip-deep in that feeding frenzy.

"My research has been in the Gallatin Canyon," said Creel, where elk inhabit four drainages. Wolves come and go, he said, enabling him to study what elk do in the presence and absence of wolves.

"Elk have proven to be pretty adaptable," Creel said. "When wolves are around, they're more vigilant and do less foraging."

Elk move into heavy timber when wolves are around, Creel added, but return to the grassy, open meadows when wolves go away. Creel and other researchers are still working out what that means in terms of the elk's diet and whether there are costs associated with this behavior.

Rather surprisingly, elk herd size breaks up into smaller units when wolves are around, said Creel, who had expected herd size to get bigger as a defense mechanism. "I think they're trying to avoid encounters with wolves," he said, by being more vigilant, moving into the timber and gathering in smaller herd units.

Yellowstone Wolves are Food Distributors

Researchers have also determined that wolves, in the recent absence of hard winters, are now the primary reason for elk mortality. Before wolf reintroduction, deep snows were the main determinant of whether an elk was going to die.

Researchers from the University of California at Berkeley determined that the combination of less snow and more wolves has benefited scavengers both big and small, from ravens to grizzly bears.

Instead of a boom and bust cycle of elk carrion availability-as existed before wolves and when winters were harder-there's now a more equitable distribution of carrion throughout winter and early spring, said Chris Wilmers in the on-line journal Public Library of Science Biology. He added that scavengers that once relied on winter-killed elk for food now depend on wolf-killed elk. That benefits ravens, eagles, magpies, coyotes and bears (grizzly and black), especially as the bears emerge hungry from hibernation.

"I call it food for the masses," said Ed Bangs, wolf recovery coordinator for the U.S. Fish and Wildlife Service. He said he was genuinely surprised by the vast web of life that is linked to wolf kills. "Beetles, wolverine, lynx and more," he said. "It turns out that the Indian legends of ravens following wolves are true-they do follow them because wolves mean food."

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On a quiet spring morning, a resounding "Slap!" reverberates through the air above a remote stream leading to Lake Yellowstone. Over much of the past century, it has been a rarely heard noise in the soundscape that is Yellowstone National Park, but today is growing more common-the sound of a beaver slapping its tail on the water as a warning to other beavers.

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I think that the elk need the wolves to survive. In the graph it showed that when the wolves were introduced the death by starvation dropped from 500 to zero. this happens because when there are a lot of deer they eat all of there food and starve to death. this leaves their predators with nothing to eat and so it kills them. with them gone the whole ecosystem comes crashing down.

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In the graph it shows that when the wolves were coming back that the elk declined dramatically. The articles said when the elk dropped dramatically that beaver and willow populations rose. Apparently the elk had been eating all of the young willows giving the beavers nothing to eat in the winter. But when the wolves came and killed off the deer the beaver and willow populations bloomed. The moose were not part of this web but their populations declined because of loss of habitat, disease, and parasites.

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In the bear necessities, when there was a lot of bears it was harder to get food and people had to steal others food just to survive. at the end of those days several bears died. the carrying capacity of that ecosystem stayed mostly the same but with more consumers means more competition. In the coral reef gizmo when snapper, angelfish, and parrot fish died off with no food the groupers also began to die off. everything depends on something else in an ecosystem and if that thing dies off every organism is affected. this is caused by humans who over fish, pollute, or introduce a invasive species.

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I think that wolves shouldn't be controlled because the gray wolf was almost hunted to extinction and now only cover 15% of the territory that they once did. Wolves also are being removed from the endangered species list and unlike other animals, they're removal didn't follow any of the guidelines made by the ESA. Wolves keep the deer population down and stop the tragedy of the commons from happening in the wild. If the wolves are removed then the tragedy of the commons will happen to the park. this means all of the parks herbivores would die and yellow stone could lose some major business. In the areas around yellow stone they earn $680.3 billion dollars.

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https://docs.google.com/presentation/d/14zWqt-EUOJ0dm4IjjL_k7_MRw78Ks_qniaJ7jdgHWSI/edit#slide=id.g2c5f0cc202_0_5

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In 1973, a federal law was enacted to protect endangered and threatened plants and animals, as well as the habitats in which they live. The development of this law, known as the Endangered Species Act (ESA), was guided by an ethic new to conservation at the time, that healthy landscapes depend upon the presence of native plants and animals.

In addition to providing protection from extinction, the ESA also mandated that species nearly eliminated be restored to their historic lands. This opened up the possibility of reintroducing animals lost from the American landscape as a result of human activity, like the gray wolf.

In 1974, Congress listed the gray wolf as endangered under the ESA. However, it wasn't until two decades later that wolves were finally restored to their former habitat in the American West. In 1995 and again in 1996, gray wolves were captured in Canada and relocated to Yellowstone National Park and central Idaho.

Since reintroduction, wolves have dispersed throughout the region, returning to ecosystems that had long suffered in their absence. They are currently found in Idaho, Montana, Wyoming, Washington, Oregon and Northern California. Still, they have not yet been reestablished in the wild areas of their former range: Colorado, Utah, Nevada and large portions of other Western states where the wolf population stands at zero.

Historically, species have been "delisted" (or removed) from the list of endangered species once they've made a broad-scale recovery throughout their historical range. Delisting has been based on carefully made, evidence-based decisions. Not so for the wolf. In spring of 2011, Congress removed Endangered Species Act (ESA) protections for wolves in Idaho and Montana with an 11th hour Congressional rider attached to the federal budget bill... a must-pass measure that had nothing to do with wolves. In the face of a government shutdown, the delisting of wolves was never discussed, as the budget bill was fast tracked. Politics derailed science, the legal process outlined by the ESA was ignored, and now almost all wolves have been delisted nearly everywhere they live, with no scientific or legal justification.

In 2013, the U.S. Fish and Wildlife Service proposed removing federal protections for gray wolves (Canis lupus) throughout their historic range in the lower 48 states. Since wolves have not yet returned to all of their historic range, they face a premature ending to a recovery far from complete. The law clearly states that these decisions must be based on "the best available science," so an independent peer review was enlisted to evaluate the scientific integrity of the proposed delisting rule. That peer review unanimously found that the rule was not based on the best available science. The ruling, however, was not rescinded. The final decision as to whether or not this proposal will become law is still pending.

Gray wolves are currently only protected by the federal ESA in Oregon and Washington's Cascade Mountains (where 2-4 packs currently live), in Wyoming, the Great Lakes region, and for the critically endangered Mexican gray wolf in Arizona and New Mexico. Federal ESA protections were reinstated for wolves in Wyoming in September 2014 by U.S. District Court's Judge Amy Berman Jackson's ruling which found that the state of Wyoming's wolf management plan was flawed and irresponsible, treating wolves as "vermin" to be killed-on-sight year round without limit or need for a license in 83% of the state. Federal ESA protections for gray wolves were similarly reinstated in the Great Lakes region (including Wisconsin, Minnesota, and Michigan) in December of 2014 by U.S. District Judge Beryl Howell who ruled that the U.S. FWS decision that prematurely removed ESA protections for gray wolves in the region in 2102 was "arbitrary and capricious" and violated the ESA. Representatives from Wyoming, Minnesota, Wisconsin, and Michigan, in response to these Federal court decisions, introduced bills to legislatively remove ESA protections for gray wolves in Wyoming and in the Western Great Lakes region and to make wolves in these places permanently ineligible for protection under the ESA.

The gray wolf was brought back by the mandate of the ESA, with our federal tax dollars. They live on federal lands, land that belongs to us all. We all have a say in the future and well-being of this animal and an obligation to guarantee its safety. Wolves need your support, learn how you can help and who to contact.

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The Political Debate about Wolf Reintroduction - Living with Wolves

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In 1973, a federal law was enacted to protect endangered and threatened plants and animals, as well as the habitats in which they live. The development of this law, known as the Endangered Species Act (ESA), was guided by an ethic new to conservation at the time, that healthy landscapes depend upon the presence of native plants and animals.