Wolf Management

Duration:

27 minutes, 58 seconds

To celebrate Yellowstone's 150th anniversary, senior wildlife biologist Doug Smith talks about the past, present, and future of wolf management in Yellowstone National Park.

 

Wolf management in Yellowstone involves strategies for both the short and long term. Over time, we keep track of the wolf population to learn how they live, interact with each other, and affect other wildlife. To do this, we use tools like radio collars, remote cameras, sound recordings, and direct observations. This research helps us make decisions about managing the park's natural resources, create educational programs, and work with other agencies and groups interested in wildlife management.

 

 

Our Goals

We study wolves to understand how they behave as individuals, how they interact within and between packs, and how they influence the ecosystem as apex predators.
Bringing wolves back to Yellowstone after nearly 70 years is a major conservation success. Our monitoring and research gives us valuable insights into their population health, social behavior, interactions with prey, relationships with other predators, and impact on the food web.

We work to ensure wolves stay wild.
In the park, we manage roadside carcasses, temporarily close areas near wolf dens, and ensure wolves don’t access human food. Outside the park, we share information with wildlife agencies and others to help manage issues like state-managed wolf hunting near the park and conflicts between wolves, humans, or livestock.

We provide educational opportunities for the public to understand and appreciate wild wolves in their natural habitat.
Yellowstone is one of the best places in the world to see wild wolves. We teach visitors how to watch wolves safely to avoid disturbing them and to protect both wolves and people. Our research, monitoring, and education efforts help create a world-class experience for visitors to watch and learn about wolves.

 

Dan Stahler, senior wildlife biologist, using VHF telemetry equipment

NPS / Jacob W. Frank

Long-Term Monitoring & Research

Long-term monitoring and research are vital for managing wildlife because ecosystems and species relationships are always changing. Since wolves were reintroduced to Yellowstone in 1995, we’ve collected long-term data to gain valuable insights about them. We gather much of this information by tracking wolves with radio collars. We also use noninvasive tools like sound recordings and remote cameras to better understand wolf behavior and their role in the ecosystem.

Wolf Capture

We track most wolf packs by fitting some individuals with radio collars during winter capture efforts, usually done using helicopters with darting or net-gunning techniques. These collars can be GPS (global positioning system) collars, which send daily location data via satellite, or VHF (very high frequency) collars, which are tracked from the ground or air. We aim to collar about 30% of each pack to account for losses due to wolf deaths, collar failures, or wolves leaving to join or form new packs inside or outside the park.We focus on collaring key wolves, like breeders and pups, and replacing older or failed collars. During captures, we collect blood samples, record weight and body measurements, and determine the wolf’s sex and age. This radio-collared population, combined with monitoring data, supports long-term research, guides management actions in the park, and helps with decisions within and beyond Yellowstone’s boundaries.

Genetics & Disease

Yellowstone collects DNA samples from all wolves we handle or find deceased to create genetic profiles. These profiles help us study how wolves evolve, maintain population health, and relate to one another. They also show how genetic traits influence their appearance, behavior, survival, and reproduction.Using this data, we estimate relationships within and between packs, including parentage and sibling ties. This helps us track reproduction and identify wolves moving in or out of the park—important for understanding population health and long-term survival. We also use hair and fecal samples to estimate population size and analyze blood and tissue to detect diseases and their effects on wolf health and behavior.

 

Using radio collars, biologists can study wolf survival, mortality, immigration, and emigration; location of dens, rendezvous sites, and pup numbers; pack structure, spatial organization, and territory size; and seasonal food habits.

 

Wolf biologist Matt Metz changing batteries on an autonomous recording unit

NPS / Jacob W. Frank

Population Size & Social Behavior

We conduct two population counts each year. The first, from mid-November to mid-December, shows the maximum population after pups have stabilized. The second, in March, reflects the population at the end of the biological year, just before denning season in late April.

These observations help us track survival, mortality, and movements of individual wolves. Radio-tracking also reveals details about pack dynamics, such as pack size, the roles of breeders, territory use, den locations, and long-term pack stability. We also study interactions between packs, like territorial behavior, scent marking, and howling, to better understand their social structure.

Our latest research uses autonomous recording units (ARUs) to capture wolf howls throughout the park. This helps us study the patterns and purposes of howling and develop bioacoustic methods to estimate wolf numbers. These techniques are particularly useful in remote areas where direct observation is difficult. By combining data from radio collars with noninvasive tools like ARUs and remote cameras, we aim to enhance wolf population monitoring in Yellowstone and beyond.

 

Wolf-Prey Relationships

We study wolf-prey relationships by examining wolf diets and how often they hunt and scavenge. While we collect diet data year-round, we focus on specific seasons: early winter (mid-November to mid-December), late winter (March), and spring-summer (May–July).To better understand these interactions, we monitor the northern elk herd by fitting adult female elk with radio collars. This provides information to help us estimate the elk population, such as: survival, causes of death, habitat use, migration, and how likely elk are to be seen during aerial surveys. We also plan to revisit studies on elk calves, last conducted in 2003–2005, which showed bears as the main predators of newborn calves.By analyzing GPS data from wolves and elk, we study how wolf presence, numbers, and kill locations affect elk movements. This research shows how wolves indirectly impact the ecosystem, including their role in food web dynamics and trophic cascades. A trophic cascade happens when changes at the top of the food chain, like wolf behavior, cause a ripple effect through other species and habitats, shaping the entire ecosystem.

Winter Predation Study

Our Winter Study, conducted every year since wolves were reintroduced to Yellowstone in 1995, takes place during early and late winter. Over these two 30-day periods, we study what wolves eat by identifying the type of prey (such as elk, bison, or deer), as well as the prey’s sex and age, and how often wolves feed. We also examine feeding sites to see if prey were killed or scavenged, looking for clues like blood or the prey’s nutritional condition.We detect feeding events through ground and aerial observations or by investigating clusters of wolf GPS locations. While we can’t find every feeding event, combining these methods helps us estimate the ones we miss for each pack. During this time, we also observe wolf hunting behaviors to learn how factors like prey species, group size, or the age of wolves affect their hunting success.

 

Biologists visit all wolf kills occurring during Winter Study to determine species, sex, age, and condition of prey killed by wolves.

 

Summer Predation Study

In the spring-summer period, we conduct our Summer Predation Study. During this time, wolves often forage in multiple groups and feed on smaller, newborn ungulates. Using GPS cluster searches, we systematically locate carcasses to understand what wolves eat and how frequently, focusing on seasonal variation in wolf diet.

Interactions with Other Species

Yellowstone biologists work with outside researchers to study how wolves, bears, and cougars interact in the Northern Range, using GPS collars to track their movements. For example, we’ve studied how bears affect wolf hunting and how bears or wolves influence cougar hunting. These studies help us understand the combined effects of carnivores on prey populations, coexistence, and competition.We also study how wolves indirectly provide food for scavengers. For instance, ravens benefit from wolf kills, and we plan to expand this research to other scavengers, like golden eagles. Using data such as GPS tracking, activity patterns, and remote camera footage, we explore how large carnivores and the carrion they leave behind affect scavenger behavior and decision-making.

 

Duration:

1 minute, 11 seconds

On the morning of October 21, 2021 visitors watching wildlife in Yellowstone’s northern range were amazed when they saw an adult grizzly bear seemingly hunting elk with the Junction Butte wolf pack near Hellroaring Creek.

 

Hundreds of people safely watch wildlife feed on a bison carcass in Hayden Valley.

NPS / Jacob W. Frank

Managing the Human-Wolf Interface

Wolves are very popular with visitors, and because they can often be seen, we sometimes need to manage interactions between wolves and people. This includes temporarily closing sensitive areas, managing traffic to protect both wolves and visitors, and occasionally hazing wolves to keep them from becoming too comfortable around people. These actions are based on years of experience and data from radio collars. This information also helps guide discussions with stakeholders and nearby wildlife management agencies about the shared Yellowstone wolf population.

Roadside Viewing of Wolves

Yellowstone is known as the best place in the world to see wild wolves, an attraction that brings over $80 million annually to local communities. However, this also means visitors often come close to wolves, requiring careful management to ensure safety, protect wildlife, and provide a world-class visitor experience.Park rules require people to stay at least 100 yards away from wolves, bears, and cougars and prohibit disturbing or approaching wildlife, but park staff often manage viewing opportunities at even greater distances to maintain safety. No-stopping zones might be created if wolves make a kill near a road. In some cases, carcasses are moved farther from roads to reduce risks while still allowing wildlife access. These decisions are made situationally, prioritizing visitor and wildlife safety first, followed by protecting resources and ensuring visitor enjoyment.

 

Predator-prey chases happen countless times every day in Yellowstone, but we rarely witness them. Kira Cassidy, research associate with the Yellowstone Wolf Project, provides context and insight as a wolf tests an elk along Soda Butte Creek.

 

Wolf Homesites

To protect active wolf homesites during sensitive periods, the park may temporarily close certain areas. Homesites include dens, where pups are born and spend early summer, and rendezvous sites, where packs care for pups until they’re old enough to travel. These closures, lasting from a few weeks to a few months, are decided case by case to minimize disturbances during this critical time.

Most wolf packs choose remote backcountry homesites that require little management. However, when homesites are visible or discovered by visitors, intervention may be needed. Human activity near homesites can cause wolves to abandon the area and move their pups, increasing the risk of pup deaths. Frequent disturbances can also make wolves too comfortable around people, leading to unwanted behaviors.

While some homesites can be safely observed from a distance and enjoyed by thousands of visitors, closures aimed at reducing disturbances can also enhance visitor experiences by promoting responsible wildlife viewing and protecting the natural behavior of wolves.

 

Duration:

41.267 seconds

In the absence of food, wolf will sometimes bring "toys" to dens sites for their pups. This series of remote cameras captured clips of the Mollie's Pack doing just that.

 

Wolf travels in the roadway after a snowstorm.

NPS / Jacob W. Frank

Wolf Habituation

Wolves rarely pose a threat to people, but if they become too comfortable around humans, safety concerns can arise. Preventing wolves from losing their natural wariness of humans is a key goal of Yellowstone’s wolf management. This is why the park may temporarily stop traffic to let wolves cross a road or close areas near carcasses or dens to reduce disturbances.

Feeding wolves—or any wildlife—is strictly prohibited because it can quickly lead to habituation. Even behaviors like wolves traveling on snow-free or groomed roads can contribute to this problem. Managing these situations can be challenging, especially when wolves are drawn to roads for easier travel. Visitors play an important role by giving wolves plenty of space and allowing them to leave roads naturally.

If wolves start showing signs of being too comfortable around people, park staff may use techniques like hazing to discourage this behavior and reinforce their natural caution. These efforts help prevent habituation and ensure safer interactions between wolves and visitors.

Hazing Operations

Hazing is a step-by-step process that starts with mild actions and increases in intensity if the wolf doesn’t respond. Low-level hazing methods include yelling, honking a car horn, or using a siren from a ranger’s vehicle. Mid-level hazing uses biodegradable paintball rounds, which are safe for wolves and easy for park staff to handle and train with.

More intense hazing methods involve nonlethal tools like beanbag rounds or rubber bullets, which have more impact than paintballs. Another option is cracker shells, which are fired from a shotgun and create a loud explosion overhead to scare the wolf away.

Hazing is considered successful if the wolf stops showing habituated behavior within a year. If these methods fail and the wolf is seen as a potential danger to people, it may be removed from the population. Since wolves were reintroduced to Yellowstone in 1995, only two wolves have been removed due to habituation. In both cases, the wolves had likely been fed by humans, leading to irreversible food conditioning and behavior changes.

 

2023 Yellowstone wolf pack territories.
*No radio collars present in Firehole River pack, unable to estimate territory size.
**1386F Group not present at end of the year.

Working Across Boundaries

Most wolves in Yellowstone stay within the park, contributing to Wyoming's annual wolf population counts as required by U.S. Fish and Wildlife Service guidelines for Endangered Species Act delisting. However, some packs have territories that extend beyond the park's boundaries, occasionally moving into neighboring states of Idaho, Montana, and Wyoming. These movements often happen during the fall elk migration, which overlaps with state-managed hunting seasons.

When wolves leave the park, they are subject to state wildlife regulations, including legal hunting during designated seasons. Yellowstone works with neighboring states by sharing data on wolf pack sizes, movements, and time spent outside the park to support state management decisions. The park also collaborates with state agencies to determine if wolves killed—legally or illegally—were part of packs that primarily live in Yellowstone.

Since wolves were delisted, some Yellowstone wolves are legally hunted each year under state-specific quotas, which vary by location and season. Ongoing research examines how hunting affects the park's wolf population, including its impacts on pack stability, pup survival, social behavior, and genetic health. This research helps us understand the broader effects of human-caused mortality on Yellowstone’s wolves.

 

Yellowstone Forever group watching wolves in Lamar Valley.

NPS / Jacob W. Frank

Education & Outreach

We are committed to educating both the public and the scientific community about wolves. In the field, our staff track wolves, collect data, and share their knowledge with visitors. When wolves are visible, we often set up spotting scopes and talk with visitors about Yellowstone’s wolf population, their history of removal and recovery, and their role in the park’s ecosystem. These interactions educate visitors while supporting the National Park Service’s mission to provide a world-class experience focused on protecting and preserving resources.

Each year, we reach tens of thousands of visitors through these roadside discussions. Beyond the field, we deliver hundreds of presentations to schools and universities, create video content, participate in media interviews, lead ranger programs, and share insights through podcasts. Our annual report keeps the public informed about wolf populations, prey interactions, and other ecological factors. Our nonprofit partner, Yellowstone Forever, also provides valuable educational content about wolves.

For the scientific community, we present our findings at conferences and work with university and agency scientists to publish peer-reviewed research. These publications contribute to better wolf management practices in Yellowstone and other areas where wolves are present.

Questions & Answers

 

How many wolves are currently in the park?

As of January 2024, there are at least 110 wolves in the park. Nine packs were noted. Wolves in Yellowstone sit at the core of a larger population connected throughout the Greater Yellowstone Ecosystem.

Does Yellowstone have a desired number of wolves to manage for?

No. We do not have a particular number that we manage for. Instead, our policy is that the population is determined by natural processes.  We monitor the number of wolves and packs, and the processes that affect these measures (e.g., births, deaths, immigration, emigration, prey abundance, etc.) to assess important factors that influence the Yellowstone population. We also monitor for diseases and measure genetic viability to evaluate overall population health, which allows us to assess if direct management of wolf abundance is needed.

Overall, the protection of wolves and the prey abundance that supports them within Yellowstone allowed a healthy wolf population to persist since reintroduction. This population sits at the core of a larger population of wolves throughout the Greater Yellowstone Ecosystem and beyond.

What have we learned about wolves in Yellowstone since their reintroduction 30 years ago?

From reintroduction to present day, studies of wolves in Yellowstone continue to provide new scientific discoveries about this species' biology, their dynamic relationship with prey and other carnivores, and their impacts on Yellowstone's diverse food web and ecological processes. Underlying these scientific discoveries has been the unique opportunity to observe individual wolves throughout their lives, the packs they belong to, and behaviors associated with hunting, raising families, and interacting with other species.

From this, we've learned that Yellowstone wolves live in complex social groups, where the age, sex, and genetic composition of pack, and overall pack size, has important influence on the survival and reproductive success of individuals, and the pack's ability to hunt large prey, defend territory, and persist. In general, packs that are larger, and have older, bigger, and more experienced wolves, are more successful. Importantly, these attributes are more likely in Yellowstone due to the protection the park offers to wolves that live here.

We've also seen significant shifts in wolves' relationship with prey. In the first decade of wolf recovery, elk have been of primary importance to wolf diet, with wolves playing a relatively small role in elk population dynamics compared to human hunting outside the park, winter severity, and droughts. Now, the entire community of predators, including wolves, cougars, grizzly bears, black bears, and humans, all collectively influence elk population regulation.

Over the last decade, bison play an ever-increasing importance to wolf diet as they have increased in abundance, largely through scavenging. Wolves also have influenced other aspects of Yellowstone's food web, such as the scavenger community who benefit from their kills and even have played a role in changes observed in some vegetation communities including willow and aspen.

Finally, we find wolves being important to the Yellowstone visitor, with people from around the world coming to see this charismatic species as part of the world-class experience Yellowstone offers. A key insight is that the Yellowstone we see today holds one of the most rich and abundant diversity of large mammals coexisting and thriving since the establishment of the park. And wolves are part of this story. These findings underscore the critical role of long-term ecological studies in understanding and managing biodiversity, as ecosystems remain ever-changing and interconnected.

A compiled summary of much of what we have learned can be found in the book, Yellowstone Wolves: Science and Discovery in the World's First National Park (editors Smith, Stahler, and MacNulty, University of Chicago Press, 2020).

Why were wolves reintroduced into Yellowstone?

Wolves were reintroduced to Yellowstone National Park in 1995 to restore native species and reestablish the essential ecological role of predation. Their removal in the early 20th century caused elk overpopulation, leading to overgrazing and disrupting the natural food web. As a keystone species, wolves play a critical role in maintaining ecosystem balance. Their return restored predator-prey interactions, boosted biodiversity, and addressed human-caused ecological imbalances, marking a major conservation achievement.

The reintroduction followed decades of effort inspired by two key milestones. The 1963 Leopold Report recommended restoring predators to maintain ecological integrity in national parks. The 1973 Endangered Species Act provided legal tools to prevent extinctions and recover species, paving the way for wolf recovery.

After extensive research, including the Wolves for Yellowstone studies and an Environmental Impact Statement, wolves were reintroduced to Yellowstone and central Idaho. This completed Yellowstone's predator community, fulfilled a major Leopold Report goal, and reestablished predation as a foundation of the park's ecosystem.

How much support does Yellowstone Forever provide to the Wolf Management Program?

Each year, Yellowstone Forever provides the wolf program with over $1.5 million in support and funds three biological science technicians, two research associates, and six to eight seasonal positions.

Did Yellowstone introduce the wrong wolf?

No. There is no scientific evidence to support claims that the wolves reintroduced to Yellowstone from Canada and northern Montana were significantly different from the wolves historically found in the region. Over time, taxonomic classifications of North American wolves have changed. In 1944, 24 subspecies were identified, including Canis lupus irremotus, thought to be the wolf historically present in Yellowstone. By 1995, this was simplified to five subspecies using modern statistical methods. The Yellowstone wolf, previously classified as Canis lupus irremotus, was reclassified under Canis lupus nubilus, a subspecies that ranged across much of the western and central U.S. To the north, the primary subspecies is Canis lupus occidentalis, or the northern timber wolf.

While there are genetic and physical differences between C. l. nubilus and C. l. occidentalis, their ranges overlap, and the boundaries between them are unclear. Wolves are highly adaptable and travel long distances, often interbreeding and mixing traits. This makes it more accurate to describe wolves as ecotypes—regional variations shaped by their environment—rather than as separate subspecies.

There was never a natural barrier between Yellowstone and Canada that would have stopped wolves from interbreeding. The wolves reintroduced to Yellowstone came from populations that hunted similar prey and looked and behaved much like the wolves that originally lived in Yellowstone and naturally returned to northern Montana before the reintroduction.

How does the Greater Yellowstone Ecosystem benefit from having wolves?

The return of wolves to the Greater Yellowstone Ecosystem (GYE) completed its large carnivore community, which includes wolves, cougars, grizzly bears, and black bears. The GYE is one of the few places in the lower 48 states with a full set of large predators, helping to shape the ecosystem's structure and function. This group of carnivores supports biodiversity at many levels of the food web, aligning with the National Park Service’s (NPS) goal of allowing natural processes to guide park management.

Wolf restoration also brings significant benefits to people. Wolves have economic, cultural, spiritual, and intrinsic value, and their presence directly enhances visitor experiences—an essential part of Yellowstone’s mission. Wolf-watching has become a major draw for millions of visitors, contributing over $80 million each year to the GYE’s economy, according to one study.

At the same time, wolf recovery comes with challenges. Within Yellowstone, conflicts with people and livestock are rare, but outside the park, wolves can sometimes harass or kill livestock like cattle, horses, or pack animals. Some also view wolves as competitors for game species such as elk or deer. Managing these interactions requires ongoing effort and collaboration among local communities, wildlife professionals, and stakeholders.

Why do we collar wolves in Yellowstone?

Since their reintroduction, radio collars have been essential for monitoring and researching Yellowstone’s wolves. Each year, park staff attach new collars or replace old ones under guidelines approved by NPS veterinarians. These collars include VHF (Very High Frequency) collars, which emit a tracking signal, and GPS (Global Positioning System) collars, which provide both signals and location data. This technology allows biologists to track individuals and packs, study behavior, map territories, monitor survival and movement, and observe interactions with other species.

Radio collars have been critical for scientific discoveries and conservation, offering valuable insights into wolf behavior and ecology. New noninvasive tools, such as sound recorders, remote cameras, and genetic sampling, are being tested to reduce reliance on collars. However, collars are still necessary for certain tasks, like protecting den sites, managing habituated wolves, and coordinating with other agencies on wolves that cross park boundaries.

Although helicopter captures may cause brief disturbance, wolves return to normal behavior within hours. Research shows collars do not affect wolves’ behavior, movement, survival, breeding, or pack leadership, making them a minimally invasive and highly effective tool for research and management.See inset piece for the 2018 Annual Wolf Report titled "Using Radio Collars to Study Yellowstone Wolves" to learn more:  https://www.nps.gov/yell/learn/nature/upload/2018-Wolf-Report_web-2.pdf.

 

What are some challenges of managing a carnivore species that crosses park boundaries?

Managing wolves across political boundaries is challenging due to differing wildlife management regulations, goals, and values. These variations affect how agencies, stakeholders, and the public approach wildlife and resource management.

Yellowstone wolves spend over 95% of their time within park boundaries. However, their territorial and foraging movements occasionally take them outside the park, where they are subject to state regulations, including hunting. In areas near Yellowstone, hunting in Wyoming, Idaho, and Montana sometimes leads to the loss of wolves that primarily live in the park.

To address this, Yellowstone works with state agencies to reduce human-caused wolf mortality. The park recommends strategies like smaller hunting zones and quotas to limit the impact of hunting and spread it across multiple packs.

Collaboration with state agencies, stakeholders, and the public is essential for making science-based decisions and finding shared solutions. Yellowstone shares data on wolf populations and their effects on prey species, such as elk, to help guide management strategies and foster understanding between jurisdictions.

How have wolves affected prey populations?

Wolves in Yellowstone primarily hunt elk and bison. While they kill a small number of bison, their impact on the overall bison population has been minimal. Wolves have had a more noticeable effect on elk, especially the Northern Range elk population, though this has changed over time.

In the early years after reintroduction, wolves killed only a small percentage of elk, with little impact on their numbers. Studies showed that early declines in elk populations were mostly due to effects from the climate and human hunting. Over time, wolves began preying on a larger share of the elk population, playing a bigger role in controlling elk numbers. Today, wolves, along with other predators (cougars, grizzly bears, and black bears), as well as weather patterns, are key factors shaping Northern Range elk populations.

Outside the park, Northern Range elk numbers have stayed relatively stable since wolves were reintroduced. However, differences in elk abundance inside and outside the park have led to changes in hunting regulations about a decade after wolves returned. Factors like human hunting, fewer predators, and irrigated farmland influence elk populations outside the park.

Wolves sometimes prey on deer, though their impact on deer populations is unclear. They occasionally hunt moose, bighorn sheep, and pronghorn, but any effects on these species are likely small, as their populations in Yellowstone have shown little change overall.

Do wolves kill for sport, or kill more than they can eat?

No. Wolves rely on vulnerable prey to hunt successfully, as hunting large animals is difficult and dangerous. Unlike specialized predators like cougars, wolves have a more generalized skeletal structure and are limited by factors like age, size, and the need for cooperation within their pack. These biological constraints, combined with prey defenses like size, group living, and anti-predator behaviors, prevent wolves from killing indiscriminately or “for sport.”

Sometimes, wolves may kill more prey than they can eat immediately, especially under conditions like deep snow or during group hunts. However, this behavior is not wasteful. Wolves often return to feed on leftover carcasses later, unless disturbed by humans or other factors. For instance, when prey is killed near roads or trails, traffic noise or human activity might cause wolves to temporarily abandon the carcass, creating the impression of “sport killing.”

In rare cases where wolves kill multiple prey at once, it is usually because they encountered several vulnerable animals, triggering a response to take advantage of the opportunity. These events, while uncommon, reflect natural hunting behavior rather than unnecessary killing.

Do wolf hunts outside Yellowstone affect packs living primarily inside the park?

Wolf hunts outside Yellowstone can negatively affect the survival of wolves that primarily live within the park. The extent of this impact depends on the hunting regulations set by state agencies. For example, Montana’s smaller hunting quotas north of Yellowstone have helped reduce the effects of hunting on wolf survival compared to seasons with no quotas or unlimited hunting.

Human-caused deaths, including hunting, also influence whether a wolf pack can survive and reproduce the following year. The impact varies based on pack size and whether the loss involves a breeding wolf. While the overall effect of human-caused mortality on Yellowstone's wolf population is uncertain, these deaths account for less than 5% of the population most years. This low percentage reflects the efforts of the National Park Service, state agencies, and stakeholders to minimize human-caused mortality and protect the park’s wolves.

Should people be afraid of wolves?

No. Wolves are naturally wary of humans, a trait shaped by their risk-averse behaviors and past persecution by people. While no wolf has ever attacked a human in Yellowstone, there have been a few attacks in other locations, highlighting the potential for wildlife to act aggressively toward humans under certain circumstances. Like coyotes and bears, wolves can quickly associate campgrounds, picnic areas, and roads with food, especially if they have received food rewards from these places or people. This association can lead to bold or aggressive behavior toward humans. As a result, two food-conditioned wolves in Yellowstone have been removed over the past 30 years since their reintroduction.

What can people do to keep wolves wild in Yellowstone?

• Never feed a wolf or any other wildlife.
• Do not leave food or garbage outside unattended. Make sure the door is shut on a garbage can or dumpster after you deposit a bag of trash.
• Treat wolves with the same respect you give any other wild animal. If you see a wolf, do not approach it.
• Never leave small children unattended.
• If you have a dog, keep it leashed.
• If you are concerned about a wolf—it’s too close or is not showing sufficient fear of humans— do not run. Stop, stand tall, and watch what the wolf does. If it approaches, wave your arms, yell, flare your jacket. If it continues, throw something at it or use bear pepper spray. Group up with other people and continue waving and yelling.
• Report the presence of wolves near developed areas or any wolf behaving strangely.

 

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