the wolves of yellowstone take home independent assignment

2-FOR-1 GA TICKETS WITH OUTSIDE+

Don’t miss Thundercat, Fleet Foxes, and more at the Outside Festival.

GET TICKETS

BEST WEEK EVER

Try out unlimited access with 7 days of Outside+ for free.

Start Your Free Trial

Powered by Outside

Wolf Reintroduction Changes Ecosystem in Yellowstone

Wolves are causing a trophic cascade of ecological change, including helping to increase beaver populations and bring back aspen, and vegetation..

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.”

Popular on Yellowstone National Park

Get a free Yellowstone trip planner with inspiring itineraries and essential information.

Healthy Living

• Clean Eating
• Vegetarian Times
• Yoga Journal
• Fly Fishing Film Tour
• National Park Trips
• Warren Miller
• Fastest Known Time
• Trail Runner
• Women's Running
• Bicycle Retailer & Industry News
• FinisherPix
• Outside Events Cycling Series
• Outside Shop

© 2024 Outside Interactive, Inc

Wolves of Yellowstone

Gray wolves were reintroduced into Yellowstone National Park in 1995, resulting in a trophic cascade through the entire ecosystem. After the wolves were driven extinct in the region nearly 100 years ago, scientists began to fully understand their role in the food web as a keystone species.

Biology, Ecology, Geography

Articles & Profiles

Media credits.

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Broadcaster

In partnership with, last updated.

March 7, 2024

User Permissions

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text on this page is printable and can be used according to our Terms of Service .

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources

• International edition
• Australia edition
• Europe edition

A rewilding triumph: wolves help to reverse Yellowstone degradation

Twenty-five years ago, the national park attempted to reintroduce wolves – now scientists are celebrating it as one of the greatest rewilding stories ever

Twenty-five years ago this month, wolves were reintroduced to Yellowstone, America’s first national park and an ecosystem dangerously out of whack owing to the extirpation of its top predator.

This monumental undertaking marked the first deliberate attempt to return a top-level carnivore to a large ecosystem. Now scientists are celebrating the gray wolves’ successful return from the brink of extinction as one of the greatest rewilding stories the world has ever seen.

“The pressure was huge with this project,” said Doug Smith, the senior wildlife biologist of the Yellowstone Wolf Project who was hired by the National Park Service (NPS) to head the reintroduction in the 1990s. “If we couldn’t do this here, on our own turf in one of the most famous parks in the world, as one of the richest nations in the world, then who could? This was an example to the globe in restoring nature.”

But because wolves are one of the most controversial animals on the planet, the recovery remains fiercely contested.

Wolves once roamed from the Arctic to Mexico, but they were hunted to eradication across the country from the 1870s onward. By 1926, the last wolf pack had been killed in Yellowstone by park employees as part of the policy of the time to eliminate all predators.

They were mythologized as a danger to humans, a menace to the ranchers settling the west and competition for big-game hunters. That mythology still persists to this day, although wolves very rarely attack people, especially compared with cougars and bears. Wolves kill 0.2% to 0.3% of available livestock.

When the Endangered Species Act (ESA) was enacted in the 70s, wolves were among the original species on the list. The ESA, a landmark piece of legislation to save declining species from extinction, compels the US Fish and Wildlife Service to protect endangered or threatened species and develop a plan for their recovery. But because wolves are so polarizing, the reintroduction did not take place until more than 20 years later.

The need for restoration was glaring. In the 70 years of the wolves’ absence, the entire Yellowstone ecosystem had fallen out of balance . Coyotes ran rampant, and the elk population exploded, overgrazing willows and aspens. Without those trees, songbirds began to decline, beavers could no longer build their dams and riverbanks started to erode. Without beaver dams and the shade from trees and other plants, water temperatures were too high for cold-water fish.

In 1995, in collaboration with Canadian agencies, 14 wolves were captured in Jasper national park and brought to Yellowstone. Smith recalls that as they transported the wolves through the park in horse trailers, people lined the roads to be part of the historic event. “Every time we stopped, visitors would come up and ask if they could pose next to the trailer. You couldn’t even see the wolves in there, but people wanted photos. That’s the presence and magic that wolves have, and that’s the first time we all felt that.”

In Yellowstone, the wolves were kept in acclimation pens for several weeks to keep their homing instincts from leading them back to Canada. Shortly after the pens were opened, though, wolf No 10 headed north and crossed the border into Montana, followed by No 9, his mate, pregnant with pups. He was illegally shot by a rancher, but she and her eight pups were rescued and moved back to the safety of park boundaries. Their bloodline can be traced to most of the wolves in the park to this day.

Scientists always knew that as the top predator, wolves were the missing piece in this ecosystem. But they were astonished at how quickly their return stimulated a transformation. The elk and deer populations started responding immediately. Within about 10 years, willows rebounded. In 20, the aspen began flourishing. Riverbanks stabilized. Songbirds returned as did beavers, eagles, foxes and badgers. “And those are just the things we have the time and funding to study,” said Smith. “There are probably myriad other effects just waiting to be discovered.”

While the restoration of wolves in Yellowstone has cost about $30m , wolf ecotourism brings in $35m annually , in an economic boom for the surrounding communities. Yellowstone is unique in the world as the best place to observe wild wolves, which are generally shy, reclusive and favor remote areas. This is as true for scientists as it is tourists, and as a result, wolf research in the park is considered far more advanced than anywhere else.

Wolves have repopulated parts of their historic range as far south as Colorado, where evidence of a pack was just discovered earlier this month, as far west as Mount Lassen in northern California, and to the doorsteps of the Cascades in eastern Oregon and Washington.

“It truly is going to go down in my career as one of those defining moments I was proud of to be part of from the beginning, that’s shaping the politics of conservation,” said Jamie Rappaport Clark, president and CEO of Defenders of Wildlife, which organized political support and legal actions for reintroduction and remains committed to restoring wolves to their historic ranges.

“At the same time, it’s not finished. We have not restored wolves to where they can and should be where it’s ecologically correct. We still have a lot of conflict, and concerns.” If state plans weren’t so “over-controlling, wolves would be running over the spine of the Rockies into the south-west today”.

When wolves were deemed recovered enough to be removed from the endangered species list, management of populations was left to each state. In Wyoming, people are allowed to shoot wolves on sight outside the borders of national parks. In Montana, it is permissible with a hunting permit.

Regardless of the challenges ahead, the thriving wolves in Yellowstone illustrate the success of the Endangered Species Act as a framework to conserve biodiversity, and a hopeful example at a time when the UN has revealed that the planet is on the brink of the sixth mass extinction.

“Absent the ESA, I am certain that wolves would never have come back,” said Clark. “Nearly 2,000 species would likely be extinct if they didn’t have the backstop of the ESA, which is this country’s commitment to the conservation and restoration of biodiversity within our borders.”

“It’s our conscience, our reminder that we’re responsible for maintaining a healthy planet now and in the future.”

• This land is your land
• National parks

More on this story

A mecca for rewilders: the community-led project restoring Scotland’s southern uplands

‘Places of the living’: bishop of Norwich calls for churchyards to be rewilded

‘A joy to watch’: UK rewilding brings endangered species back from brink

Campaigners urge Prince William to rewild Dartmoor farmland

Baby beaver born in London for first time in 400 years

European pond turtle could return to British rivers and lakes

From window boxes to farms, UK’s rewilding gurus bring out their bible

Britain is not ready for reintroduction of lynx and wolves, says Ray Mears

First wild beaver in Wales in years filmed in Pembrokeshire garden – video

Pigs and ponies join UK’s wild bison to recreate prehistoric landscape

Most viewed.

By signing up, you agree to our privacy policy .

Sign Up for our FREE Newsletter!

• Lesson Plans
• Lesson Templates
• Certificates
• Find Grants
• Fundraising

Search for Resources

You are here

Wolves of yellowstone: lesson plan.

This set of activities introduces students to the ecological impact of wolf reintroduction and the controversy surrounding the wolves, allowing students to extend their understanding and apply it to another wolf reintroduction debate that rages on today regarding Isle Royale National Park in Michigan.

Copyright © 2001 - 2024 TeacherPlanet.com ®. All rights reserved. Privacy Statement and Disclaimer Notice

Sign up for our free weekly newsletter and receive

top education news, lesson ideas, teaching tips, and more!

No thanks, I don't need to stay current on what works in education!

Classroom Activities

These classroom activities about wolf ecology were developed in 2007 by Minnesota Zoo education staff with a grant from the National Science Foundation for WolfQuest.

Be a Wolf Expert

Students will become wolf experts though research and sharing results using the jigsaw method of learning.

At the end of this activity, the student will:

• Research a wolf topic.
• Teach a wolf topic to another group of students.
• Create a concept map about their knowledge of wolves.

Get the PDF: Be a Wolf Expert

In this activity, students will simulate the interactions between a predator population of gray wolves and a prey population of deer in a forest. After collecting the data, the students will plot the data and then extend the graph to predict the populations for several more generations. Before playing, review the definitions for food chain, population, predator, and prey.

• Identify predator/prey relationships and how they co-exist in nature.
• Examine the changes that populations undergo to keep a balance in the ecosystem.
• Create a graph illustrating population changes in a predator/prey relationship.

Get the PDF: Deer Me! A Predator/Prey Simulation

Deer: Predation or Starvation

An island population of deer has no predatorsand the island is too remote for hunters. Is it better to let nature take its course with the deer population or should predators (wolves) be introduced onto the island?

• Identify predator/prey relationships and how they may or may not impact one another.
• Examine changes in populations due to human intervention.

Get the PDF: Deer: Predation or Starvation

Find Your Pack

This activity introduces students to wolf behavior and communication.

• Become familiar with how wolves use scent to identify member of their pack.
• Be aware of how habitat loss can effect wolf populations.

Get the PDF: Find Your Pack

Predator - Prey Tag

The population of a species in an area is dependant upon the limiting factors of the ecosystem. One such factor is the population or availability of food. The relationship of predator populations and prey populations is very cyclical.

• Understand that prey population will change and thus affect the predators population and visa versa.
• Create a graph modeling the predator-prey population cycle.

Get the PDF: Predator - Prey Tag

Wolf Survival is Just a Roll Away

In this simulation, students will raise a pack of wolves under 2 different conditions; without human interference and with human interference. Students will use dice to determine what happens to the wolf pack over time.

• Recognize that limiting factors — including predator/prey relationships affect wildlife populations.
• Recognize that some fluctuations in wildlife populations are natural as ecological systems undergo constant change.
• Understand how people can influence an ecosystem.

Get the PDF: Wolf Survival is Just a Roll Away

Wolf Telemetry

This is a high interest activity that allows a class to use telemetry data to track real wolves in Superior National Forest in Minnesota. Telemetry data is collected weekly, if possible. Students can select their own wolf, read background information on their wolf, and plot its movement on a map. This is a project that can run all year or for several months as students keep an eye on "their" wolf.

• Use telemetry data to map the location of a wolf over time.
• Predict and determine the wolf's territory.

Get the PDF: Wolf Telemetry

The Return of Gray Wolves to Yellowstone National Park: Right or Wrong?

Students will use the internet to explore relationships between habitats and species (specifically, the gray wolf and other species at Yellowstone National Park). Additionally, students will explore the effect of physical and human actions on living things and their environment. This lesson is a modification of a lesson from Science NetLinks.

After this activity, the student will:

• Explain the relationships between species that live in Yellowstone National Park.
• Identify conflicts that arise between humans and wolves living in the same environment.
• Use inquiry skills to draw their own conclusions regarding the controversy of the reintroduction of wolves into Yellowstone National Park.

Get the PDF: The Return of Gray Wolves to Yellowstone National Park: Right or Wrong?

Where in the World is the Wolf?

Students will use an interactive map to determine that wolves are found over much of the world.

• Predict where wolves are found in the world.
• Collect data to determine the number and species that live in various parts of the world.
• Make predictions about trends/fate of the wolf worldwide.

Get the PDF: Where in the World is the Wolf?

Why Not "The Good, Sweet Wolf"?

There are many words and phrases in the English language that make negative references to wolves. Childhood stories also portray wolves as "the bad guy", teaching children from an early age that wolves are dangerous. This lesson looks at the villain in the story of "The Three Little Pigs" as well as at a list of descriptive ways we attribute negative characteristics to wolves and how this symbolism can color how we think of wolves.

Students write their own short story showing the wolf as "the good guy". Finally, students read a variety of wolf stories from different cultures and analyze how each viewed the wolf.

• Analyze phrases/idioms with the word "wolf" in them.
• Describe the characterization of the "Big, Bad Wolf".
• Write a short story showing the wolf as "the good guy".
• Analyze a number of wolf stories to determine how various cultures viewed wolves and why they may have taken this view.

Get the PDF: Why Not "The Good, Sweet Wolf"?

Wolf Adaptations

Students will create a new wolf that can survive in a fictional habitat.

• Identify the importance of adaptations.
• Identify adaptations and the importance to the organism's survival.

Get the PDF: Wolf Adaptations

Wolf Adaptations PowerPoint

Students will create a PowerPoint presentation focusing upon wolves and their adaptations for survival.

• Demonstrate knowledge of limiting factors.
• Demonstrate knowledge about wolf habitat.
• Demonstrate knowledge of beneficial adaptations.

Get the PDF: Wolf Adaptations PowerPoint

Wolf Limiting Factors

Students will simulate a wolf and its habitat and observe what happens when the limiting factors change over time.

• Identify and describe the essential components of habitats.
• Define the limiting factors that affect wolves.
• Recognize that fluctuations in wildlife populations are a natural part of the ecosystem.

Get the PDF: Wolf Limiting Factors

Wolf Postures

This activity introduces students to wolf body postures/communication and animal observation.

• Use observation skills successfully.
• Identify and interpret wolf body postures.

Get the PDF: Wolf Postures

Wolf Recovery in North America

Two articles from the magazine Time For Kids introduce students to the Wolf restoration project as well as its successes and challenges.

• Explain how and why the wolf population was almost exterminated.
• Understand the impact on an environment when the top predator (wolf) is removed from an ecosystem.
• Compare human viewpoints of wolf reintroduction.

Get the PDF: Wolf Recovery in North America

Wolf Scientists

In this activity, the student will research a wolf scientist and present their information on a poster.

• Research a wolf scientist.
• Learn how this person contributed to the understanding of wolves.
• Create a display illustrating what was learned about the scientist.

Get the PDF: Wolf Scientists

Wolf Survival

In this simulation, some students will become wolves and the other students will be the prey of the wolf. The goal of the simulation is to have the wolves work together to survive.

• Understand predator/prey relationships.
• Define a major component of a wolf's habitat.
• Identify a limiting factor.

Get the PDF: Wolf Survival

Students collect prey and den cards to simulate wolves searching for food and shelter. They will discover how territory size, as well as food availability, can be limiting factors for a population.

• Predict how food availability affects wolf populations.
• Analyze the relationship between pack size and habitat.
• Calculate their wolf pack's food needs and food acquisition.

Get the PDF: Wolf Turf

Wolves and Farming: Livestock Depredation

The purpose of this activity is for students to understand the potential problems of raising livestock, and the role of wolves in livestock depredation.

• Understand that wolf predation on livestock is an issue with effects on both livestock owners and wolves.
• Evaluate livestock management strategies.
• See how their actions affect wildlife.
• List some problems of raising livestock near predators.

Get the PDF: Wolves and Farming: Livestock Depredation

Yellowstone Food Web

The students will create a food web diagram. This lesson takes about one or two 80 minute classes to teach the concept and work time on making the assignment.

• Demonstrate knowledge of energy flow in an ecosystem.
• Know that all species depend upon the other for survival.
• Demonstrate knowledge of terms; omnivores, carnivores, herbivores, and producers.

Get the PDF: Yellowstone Food Web

GET WOLFQUEST!

Buy wolfquest: anniversary edition for pc/mac (or the classic wolfquest 2.7, still available for ios), get wolfquest: anniversary edition, for windows and mac computers.

Get WolfQuest: Anniversary Edition , now in Early Access for PC/Mac! You'll also get the complete version of WolfQuest 2.7 with your purchase.

Your purchase comes with a Steam key, or:

Get Wolfquest 2.7 for Mobile!

Get the classic version, wolfquest 2.7, for mobile devices. (note: wolfquest 2.7 is no longer being updated. mobile users should first play the free amethyst mountain level to see if it will run properly on your device.).

• Skip to main content
• Skip to primary sidebar

Additional menu

Your Ultimate Guide to the Great Outdoors

The Wolves in Yellowstone: A Classic Conservation Story

The history of the Yellowstone wolf population is one of the most interesting conservation stories in the United States. In the course of 150 years, the wolf population in the Greater Yellowstone ecosystem went from being hunted almost to local extinction to a thriving population with up to nine different packs calling Yellowstone National Park home.

The Yellowstone wolves provide a classic example of how animal species are interconnected and the surprising fragility of large and seemingly robust ecosystems. 

Keep reading to learn about the different types of wolves that call Yellowstone home and the many ways the rest of the ecosystem depends on them.

Share this image on your site

Wolf species living in yellowstone.

The gray wolf historically called Yellowstone home and can be found there today after reintroduction efforts. Gray wolves are said to look like large German Shepherds. Their coat colors range between gray, brown, and black, with lighter fur on their faces, legs, and belly. Gray wolves have long, bushy tails that are often black-tipped.

Gray wolves are 26 to 36 inches (66.04 cm to 91.44 cm) tall at the shoulder and four to six feet (1.21 m to 1.82 m) long from nose to tail tip. Male and female gray wolves look fairly similar, with males being about fifteen to twenty percent larger than females. Male gray wolves weigh up to 130 pounds (58.96 kg) and female gray wolves weigh up to 110 pounds (49.89 kg).

Gray wolves can be both black and gray, with about an even distribution of the two colors found within the packs in Yellowstone

Life Cycle of Gray Wolves

Gray wolves have a lifespan of eight to ten years inside Yellowstone National Park and four to five years in the wild. All wolf species are usually monogamous and mate for life. Gray wolves mate in February and give birth in April. The average litter size is five pups.

Wolves live in packs and have layers of social behavior and hierarchy built into their pack structure. Most packs include an alpha male and female, with several subordinate wolves. Ten wolves is the average pack size for wolves in Yellowstone.

The leading cause of death for wolves inside Yellowstone National Park is other wolves, mostly from other packs. Human contact is the leading cause of death for wolves outside the park, from hunting and other conflicts with people outside of the national park boundaries.

Habitat and Range of Gray Wolves

Gray wolves can live in a wide range of habitats, including tundra, forests and grasslands. The historic range of gray wolves covered over half of the United States and reached from Canada to Mexico. The current range is much more limited, with gray wolf populations found in Alaska, the northern parts of Michigan, Wisconsin, and Minnesota, and parts of Montana, Idaho, Wyoming, and Oregon.

Wolves Diet

Wolves are carnivores. By working as a pack, the gray wolves in Yellowstone are able to hunt large prey that other predators in the area are unable to hunt. In the winter, elk make up about 90% of the Yellowstone wolves’ diets. In the summer, wolves are also likely to hunt deer and bison. Gray wolves will also act as scavengers when necessary, stealing and eating game killed by other carnivores.

Almost all the wolf populations in the US were gone by the 1920’s, hunted by ranchers protecting their wildlife and impacted by habitat loss as towns grew in their historic range, causing an increase of human/wildlife conflicts.

Wolf eradication in the United States was one of the most intense and successful wildlife removal programs undertaken in the country’s history. According to records, the last wolf shot inside Yellowstone National Park was killed in 1926.

The gray wolves of Yellowstone are the apex predator in their ecosystem, meaning they aren’t hunted by other predators and have access to whatever prey species are most abundant at the time. While their diet usually consists of large hooved animals, Yellowstone’s gray wolves will also eat rabbits, weasels, badgers, foxes, and other small mammals.

Wolf Wildlife Management History in Yellowstone

The environmental movement grew in the United States in the 1960s and 1970s, leading to passage of many laws designed to correct the population management mistakes made in the past in favor of restoring ecosystems to their natural state when possible.

The Endangered Species Act of 1973 was especially important. This act not only protected species currently in trouble but also recommended the restoration of native species if possible to restore the health of ecosystems. By 1978 all gray wolf subspecies were listed as federally endangered in all states except Minnesota and Alaska.

Scientists had almost seventy years to observe the Greater Yellowstone ecosystem and note important changes to ecosystem services and the dynamics of other plant and animal species without wolves. Realizing that wolf populations were an irreplaceable piece of the ecosystems, they began the process of reintroducing wolves to the Greater Yellowstone Ecosystem and started the reintroduction program in 1995. 

The 1995 reintroduction efforts were controversial. Farmers, ranchers, and hunters in the area didn’t want wolves brought back to the area because of perceived impacts to livestock like sheep and cows. There were concerns that any wolves brought to the park would quickly move outside the park boundary and come into closer contact with people and livestock or return to where they came from.

Scientists were unsure how much of the ecosystem had been impacted by the wolf population and were unable to anticipate the full depth of the importance the wolf population had on the Greater Yellowstone Ecosystem.

You may also like: Learn the 10 Keystone Species Examples and Why They Are an Important Part of the Ecosystem: Complete with Images, Descriptions, and More!

Wolves Reintroduced to Yellowstone

In January of 1995, eight gray wolves were captured in Jasper National Park in Alberta, Canada, and brought to Yellowstone National Park. Scientists continued to reintroduce gray wolves by bringing small packs to Yellowstone from other areas with healthy wolf populations, with a total of thirty-one wolves relocated to Yellowstone by the end of 1996.

Since wolf packs cover large areas and have a strong homing instinct, scientists were concerned the relocated wolves would simply head back to their homes in Canada. To make the transition more effective, three acclimation pens were built to house the wolves for several weeks. Elk carcasses were also placed in the new environment so the wolves would get an idea of what their new environment could provide: ample prey and lots of room to roam without needing to leave the Greater Yellowstone ecosystem.

Scientists also took steps to ensure the reintroduced wolves would not become acclimated to human presence during the reintroduction process. While the wolves had to come in contact with people to be captured and transported, contact was minimal once they were placed in the acclimation pens. 

Even though the wolves were brought food and monitored for health, action was taken to limit their interactions with people during these times. The reintroduction was successful in minimizing habituation to people and the wolves avoided human contact when they were released from the acclimation pens.

As expected, one alpha male immediately headed north out of the park boundaries when released. The pregnant alpha female of the same pack followed. The male was shot soon after leaving the protected boundaries of the park, but the female was recovered and brought back to Yellowstone. Her pups were born successfully and many of the wolves currently found in the Greater Yellowstone Ecosystem can be genetically linked to the first wolves brought back to Yellowstone in 1995.

The full depth of the impact wolf populations have on the Greater Yellowstone ecosystem was unknown at the time of their removal and reintroduction to the park. The reintroduction program provided a unique opportunity for scientists to observe the changes that occur when a keystone species is brought back to an area after being gone for such a long time. 

Even without knowing the full extent of their importance, scientists could see the ecosystem wasn’t functioning well and that an important species was missing. Since wolves were removed with such prejudice at the beginning of the 20th century, that was the first species to start with to improve the health of the ecosystem.

You may also like: Be Fascinated with the 27 Amazing Types of Wolves: Complete with Facts, Images, Descriptions, and More!

Why Wolves are Important in Yellowstone

In the Yellowstone ecosystem, wolves are a keystone species. This means the rest of the ecosystem functions at a lower level when wolves aren’t present. Their keystone species status was unknown when wolves were removed from Yellowstone, as that pursuit was done in the name of human/wildlife conflict without regard to the health of the overall ecosystem. 

The presence or absence of wolves in the Greater Yellowstone Ecosystem causes a trophic cascade. Trophic cascades describe the relationship apex predators have with their prey, and the relationship their prey have with their food sources. When apex predators limit the density or change the behavior of their prey, the food source of their prey changes as well. The Greater Yellowstone ecosystem’s trophic cascade directly impacted wolves, elk, and the plant species the elk eat. It also indirectly impacted beavers, scavenger species like ravens and magpies, and even the plant and fish species that rely on Yellowstone’s winding streams.

Without wolves, the elk population isn’t naturally managed. This causes overgrazing that impacts the health of other herbivore species in the area. The elk population in Yellowstone can quickly reach the ecosystem’s carrying capacity when not managed by wolves. The carrying capacity describes the size of a population the ecosystem can support. When elk exceeded the carrying capacity of Yellowstone, their regular food sources weren’t enough and elk had to expand their diet to include young willow, aspen, and cottonwood in the winter. The elk population also didn’t have to move as much during the winter because they weren’t under threat by wolves. 

As elk ate more willow in one area during the winter without moving, beaver populations were impacted. Beavers need young willows to survive through the winter. The combination of year-round grazing on willow stands beside rivers and the absence of beaver populations actually straightened the streams that run through Yellowstone, changing the riverine ecosystems.

When wolves hunt and kill elk, they’re also providing food for ravens, magpies, coyotes, and even bears. Without wolves, the scavenger species like ravens and magpies had fewer food sources. While coyotes and bears do hunt on their own, they lack the pack dynamics that allow wolves to bring down larger prey like elk and bison. Coyotes and bears rarely take down elk on their own, which means wolves are the only species that naturally control the elk population. 

In the twenty-five years that have passed since the 1995 reintroduction program, expected and unexpected changes have been observed in the Greater Yellowstone Area. Elk populations are once again under control, with the overall population breaking into smaller groups that stay on the move throughout the winter to avoid conflicts with wolf packs. 

Willow stands along streams have healthier and more robust biomass, stabilizing the stream banks and providing resources for beavers. Beaver populations are slowly returning to the park and the streams are becoming winding and meandering once again. This is only the beginning of changes that will be observed in the Greater Yellowstone Ecosystem as the wolf population continues to become established and create a positive trophic cascade, restoring the health of the ecosystem in surprising ways.

It takes time to fully understand the dynamics of an ecosystem and be able to recognize the keystone species and anticipate all of the impacts they have at trophic levels beyond just their prey populations. Only five or six other similar reintroductions have been documented, making the Yellowstone wolf reintroduction a classic conservation success story. 

You may also like: Learn the 13 Different Species of Snakes in PA: Complete with Images, Facts, Descriptions, and More!

Wolf Populations in Yellowstone

At least 123 wolves live inside Yellowstone National Park as of January 2021, with nine individual packs noted. An estimated 528 wolves live in the Greater Yellowstone Ecosystem as of 2015. Wolf population levels inside the park have fluctuated between 83 and 123 since 2009. Monitoring of the wolf population in the Greater Yellowstone Area is managed by the Yellowstone Wolf Project and the Northern Rocky Mountain Wolf Recovery Plan.

Wolf Hunting Regulations Outside Yellowstone National Park

While hunting is prohibited inside Yellowstone National Park, wolves have large territories and reside in the Greater Yellowstone area, not just inside park boundaries. When wolves leave park boundaries, hunting regulations are subject to the state they are in. The wolf populations in the Greater Yellowstone Ecosystem have rebounded so well that they’re no longer on state or federal endangered species lists, but that does open the populations up to hunting as the state management agencies see fit.

These regulations change year-to-year depending on the wolf populations throughout the state as a whole and are managed by Montana Fish, Wildlife and Parks, Wyoming Game and Fish, and Idaho Fish and Game.

You may also like: Understand What is Poaching and Why is it Practiced: With Photos, Infographic, Videos, and More!

Threats from Habitat Loss and Climate Change

Wolf populations have faced threats from habitat loss since westward expansion in the United States began. As land was converted for agriculture, natural prey species became less abundant and wolves had to adapt to using livestock species as prey or leaving the area. 

Habitat loss caused by the introduction of agriculture was more intense in the 1800’s and 1900’s, but still happens at a lower level today.

Wolf packs can cover large territories and are currently threatened by habitat fragmentation. New roadways are especially challenging. As it becomes unsafe to cross interstates and highways, wolf territories become smaller and it becomes more challenging to hunt enough prey to continue to support the pack.

At this point it’s unclear how the Yellowstone gray wolves will be impacted by climate change. Gray wolves adapt easily to different types of habitats , making changes in precipitation, temperature, and snowpack less extreme for gray wolves. However, their prey species may be more susceptible to changes caused by climate change.

Cultural Myths and Legends Associated with Gray Wolves

Like many predators, wolves are subject to the perceptions of the people around them. Wolves are often featured in Native American mythology and legends as representations of courage, loyalty, and strength. 

As settlers of European descent came into contact with wolves during westward expansion, the wolves were perceived as a dangerous presence to people and livestock and actions were taken to remove them from newly settled areas.

You may also like: How Big Are Wolves? All About The Largest Living Canines

4 Fun Facts About Yellowstone’s Wolves

• The oldest known wolf in the Yellowstone area is twelve and a half years old.
• The gene for black fur is tied to a gene for increased immune system functionality, making black-colored gray wolves more likely to survive during distemper outbreaks. Studies have found that gray-colored gray wolves are more aggressive and have higher reproductive success. Both traits are good for the population and it’s common for mating pairs of opposite colors to form.
• The average speed of a gray wolf is five miles per hour (8.04 km/h), with a top speed of thirty-five miles per hour (56.33 km/h).
• A gray wolf’s sense of smell is up to one hundred times more sensitive than a person’s sense of smell.

You may also like:

Coyotes in Texas | Wolves in Idaho | Coyotes in New Jersey

About Ann Briggs

Ann is a Science Communicator and Contributor specializing in conservation, biology, travel, science and outdoor recreation. She is passionate about helping others gain an appreciation of nature and the knowledge to get outside and experience new adventures.

Bachelor's degree in Conservation Biology and Master's in Science Communication from the University of Nebraska - Lincoln. Wilderness first aid certified and trained as a safari guide in Botswana. Enjoys hiking, camping, climbing, paddling, and exploring.

Related Posts

13 Snakes in PA : Nonvenomous to Venomous (With Pictures and Facts)

30 Different Types of Ducks (Pics, Facts & Chart)

How Long Do Bees Live? Everything You Need to Know About the Life of a Bee

Discover the Bald Uakari: The Amazon’s Red-Faced Primate Marvel

39 Fascinating Amazon Rainforest Animals, Birds & Insects

Panamanian White-Faced Capuchin: The Most Intelligent New World Monkey

• PHOTOGRAPHY

Striking Photos Capture the Wild Wolves of Yellowstone

Photographer Ronan Donovan set up hundreds of camera traps to document wolves in their natural habitat.

He gets up close and personal with some of the fiercest predators in Yellowstone. Or at least his cameras do.

For photographer Ronan Donovan camera trapping is an art, and designing the setups with animal behavior patterns in mind can require creativity, patience, and determination. On assignment for National Geographic ‘s 2016 issue on Yellowstone, he rolled up his sleeves, refused to give up, and captured amazing images of bears and wolves in their natural habitat.

Bears are naturally curious omnivores that tend to “lick everything,” Donovan says, and one of the biggest challenges in setting camera traps for them is what he calls “camera carnage.” Wolves, on the other hand, are much more elusive—and much harder to pin down.

Note: The video above features photographs that were made using a variety of techniques, including camera traps.

This bison drowned in the Yellowstone River over the winter when it tried to cross. Donovan says a grizzly bear had been feeding on this carcass for several days before he set up a camera trap.

According to Donovan, wolves are by nature more wary of anything new in their environment—even the slightest reflection from a lens could scare off an approaching wolf. Donovan spent months trying to invent ways to “trick” the wolves, building all sorts of structures to hide the traps and make them less conspicuous. One of the traps he built was disguised by a pile of river rocks and placed in the shallows of the Yellowstone River.

Not only did Donovan have the wolves’ wariness to contend with, but he also had to deal with ever changing weather patterns, which can cause a camera lens to fog or ice over. Out of the hundred traps he set in Yellowstone, only five produced viable pictures of wolves.

A group of wolves feed on the same bison carcass from the previous image. Condensation made this shot a near miss.

In one particularly heartbreaking instance, three wolves came to feed on a bison carcass on the Yellowstone River. Wolves are social animals, so photographing them together would be a coup. The camera fired a couple of thousand times, but because the lens had iced over, the shapes were rudimentary and the images unusable.

Though the wolves never again came back to that spot as a group, it wasn’t a total loss. After months of reformatting and rejiggering, Donovan’s hard work and persistence paid off with the amazing images shown in the video above.

View more of Donovan’s wolf photos in the story “ Photographer Ronan Donovan on Yellowstone .”

FREE BONUS ISSUE

Related topics.

• NATIONAL PARKS
• CAMERA TRAPS

You May Also Like

Wolves hunt sea otters and seals, a startling find

Cougars are ambushing and killing wolves—and no one knows why

These birds help humans find honey. But it’s rare—and getting rarer.

Africa's vultures are disappearing. A series of disasters could follow.

Wisconsin pays hunters whose dogs are killed by wolves. There are unintended consequences.

• Perpetual Planet
• Environment
• Paid Content

History & Culture

• History & Culture
• Photography
• Mind, Body, Wonder
• Gory Details
• 2023 in Review
• Best of the World
• Terms of Use
• Privacy Policy
• Your US State Privacy Rights
• Children's Online Privacy Policy
• Interest-Based Ads
• About Nielsen Measurement
• Do Not Sell or Share My Personal Information
• Nat Geo Home
• Attend a Live Event
• Book a Trip
• Inspire Your Kids
• Shop Nat Geo
• Visit the D.C. Museum
• Learn About Our Impact
• Support Our Mission
• Advertise With Us
• Customer Service
• Renew Subscription
• Manage Your Subscription
• Work at Nat Geo
• Sign Up for Our Newsletters
• Contribute to Protect the Planet

Copyright © 1996-2015 National Geographic Society Copyright © 2015-2024 National Geographic Partners, LLC. All rights reserved

404 Not found

This Is Love

Episode 72: The Wolves

Episode #72.

2023-08-23 05:00:08

We go searching for wolves in Yellowstone National Park, and learn about the dramatic and surprisingly relatable relationship between a powerful young wolf and the small, elderly wolf who had raised him.

This month, we’re bringing you two of our favorite episodes – two stories about the same family of wolves in Yellowstone. One is a love story. And one is a crime story. For the crime story, check out Episode 232 of Criminal . It’s called “Wolf 10.”

Rick McIntyre’s book is The Rise of Wolf 8: Witnessing the Triumph of Yellowstone’s Underdog. 

This episode was originally released in 2020.

Small Grizzly Bear Has No Fear Facing Aggressive Wolves In Yellowstone National Park

Usually having the high ground in a battle is beneficial, but it didn’t work out like that in this Yellowstone National Park standoff.

The grizzly bear in this footage shows that you don’t have to be big to fight big. Of all the animals you could choose to pick a fight with (I’m talking from the perspective of other wild animals), the grizzly bear is probably on the short list of worst predators to match up against.

Grizzlies are known to be some of the fiercest animals on the planet. This one didn’t have the full-bodied size that many grizzly bears possess (at least not yet), but it still had razor-sharp claws and incomparable strength.

That’s probably why these Yellowstone wolves challenged the bruin while also never getting all that close to the wild animal. It was a smart move by the canines, even though they actually appeared to have a size advantage on the younger bear.

Andrea Baratte, the tour guide in Yellowstone National Park that filmed this interaction, posted it to his Instagram account with the caption:

“Just after sunrise we were watching this grizzly bear guarding a bison carcass. The wolves were challenging the grizzly, but gave up soon and bedded nearby. The bear kept feeding on it for a while before leaving the carcass.”

View this post on Instagram A post shared by Andrea Baratte (@montanawild_)

That bear wasn’t letting those wolves get close to the food it had claimed as its own… at least not until it had finished its portion.

Those that viewed the video on social media pointed out the size difference between the wolves and the bear, and the numbers advantage that the canines had. The comments below go to show you how fierce the grizzly bear is regarded out in nature:

“I always forget how big wolves are until I see one next to something else.”

“The one wolf’s body language is quite submissive, so they seem to entirely recognize that this bear could be a threat to them.”

“Those wolves are f**king tanks.”

“They could only do this with a very juvenile grizzly.”

“The wolves might want to go get a couple of more friends.”

MORE FROM WHISKEY RIFF

WHISKEY RIFF RAFF PODCAST

WHISKEY RIFF SHOP

STAY ENTERTAINED

A riff on what country is really about.

Never Miss Out