The Quiet Extinction

Caribou have vanished from Montana, and scientists fear they could be beyond saving

  • 13 min to read

The harsh landscapes of the tundra and old-growth forests blanket  much of North America. Caribou herds once abundantly thrived from the western coast of Alaska to the eastern fronts of Canada, but that is no longer the case.

Caribou migrate longer distances than any other mammal on Earth. They learn to stand and walk almost immediately after birth. They run alongside their mothers within days. Mature adults can reach speeds of 45 miles per hour.


University of Montana wildlife biologist Eric Palm poses with a set of caribou antlers his team retrieved during their expedition in Alaska and the Yukon region. Palm and his fellow teammates spent time in the territories studying caribou migrations based on fire seasons that effected the species' habitats. 

While Eric Palm, a Ph.D. student at the University of Montana, feels confident chasing down a 2-day-old caribou, the same animal would be nearly uncatchable just a week later.

Palm’s research focuses on the elusive animal, which was seen near Whitefish, Montana as recently as November 2018. The final herd of the Lower 48, the South Selkirk herd, officially became extinct just weeks later, likely cementing the extinction of the species south of the Canadian border.

As part of a long-term study on calf survival, the Alaska Department of Fish and Game puts radio collars on newborn caribou from the Fortymile herd near Fairbanks. Palm first collared calves in 2017.

On the morning of Palm’s first day of collaring, the helicopter closed in when they spotted a young-looking calf. The pilot then guided the propellers to hover a few feet off the ground. As the helicopter descended, Palm stood on the edge, waiting for the pilot to give him the go-ahead. He knew when to jump after the first time.

Landing on the uneven, snow-covered terrain was jarring, and Palm worked hard sprinting down the calf. One or 2-day-old calves run slow, but each passing day their squishy hooves harden and become built for speed. 

“If they were 10 days old, there is no way I’d get to them,” said Palm later at UM’s campus. “They’d just crush me.” 

Once Palm managed to capture the baby, the four-step process happened with familiarity: He weighed the calf, identified the sex, estimated the age and clasped on a collar, which would fall off once the calf matured. The entire process took about one minute, then Palm ran back to the helicopter.

“They have a distinct smell, I don’t quite know how to describe it,” he said. “It’s kind of like a barn.”

Over two days, Palm collared 18 calves from the Fortymile herd, estimated at around 85,000 strong, a far cry from its historical estimates of 300,000.

Despite the two days of jumping from helicopters to wrangle calves, the bulk of Palm’s research in Alaska involved drones. From May to July 2017, Palm flew a drone throughout the caribou habitat in Alaska and the Yukon territory. His research collected images and cross-referenced radio collar data to determine how caribou used terrestrial lichen coverage for their migrations. During the winter months, caribou solely rely on lichen, a food most ungulates of hoofed animals, belonging to the same family as cows, deer and bison completely avoid. His goal: to understand how fire and human disturbance affect caribou migrations.


In the Hebblewhite Lab at Stone Hall, graduate student Eric Palm, 36, examines a map featuring the history of fires that have effected herds of caribou in the Alaska and Yukon territories. Palm has made three trips to Alaska and three trips to the Yukon to track and study populations of caribou. 

The Fortymile herd, which migrates throughout the area monitored by Palm, is one of only a handful of herds in North America that are either stabilizing or increasing. The majority of herds on the continent are in decline.

His research also extends to 40 herds throughout Alaska, Yukon Territory, the Northwest Territories, Alberta and British Columbia. The tale is grim: every herd he studies, minus the Fortymile herd, has steadily declined since 2000.

Proposed roads, mining projects, forestry, agriculture and oil and gas development throughout Alaska and Western Canada, including the Arctic National Wildlife Refuge, threaten caribou herds across the continent. Because of resistance from commercial interests and political stagnation, caribou present one of the greatest terrestrial conservation problems in both the U.S. and Canada.

“It’s the government’s job to step in and use these emergency provisions under the Canadian Species at Risk Act,” Palm said. “But, a lot of people’s jobs could be negatively affected by this. It’s caribou versus the economy.”

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Caribou are Tough, but Sensitive to Change

From the mountainous forests of Montana and British Columbia, to the boggy peatlands of the boreal forests in Alberta, and even out to the Alaskan tundra, caribou habitat varies dramatically.

There are currently four subspecies of caribou in North America: barren-ground, woodland, grants and peary. Barren-ground and woodland caribou represent the two largest subspecies of the social ungulate. 

Barren-ground caribou, also known as tundra or migratory caribou, migrate farther than antelope, mule deer, wolves and even their close relatives, the reindeer. Going back a  millennia, many barren-ground herds numbered in the hundreds of thousands, which is no longer the case due to changes in habitat, overhunting and climate change.

The two ecotypes of woodland caribou — boreal and mountain — were once abundant throughout Western Canada and into Washington, Idaho and Montana. According to the Committee on the Status of Endangered Species in Canada, the independent body which assesses the status of wildlife species at risk of extinction, there are three types of mountain caribou: northern, central and southern. Evolving to have smaller herds than their barren-ground counterparts, their populations never reached more than a few thousand.

The scientific recognition of distinct subspecies and ecotypes emphasizes the variance between the species. Different populations might eat, migrate and act differently.

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“Witnessing Extinction”

In 2019, a UN report highlighted the state of declining biodiversity and acceleration of species facing extinction. Caribou fall under the umbrella of one million species staring down extinction.

Scientists refer to caribou as an indicator species, which means their health shows the status of entire ecosystems. According to the National Oceanic and Atmospheric Administration, across all caribou and reindeer populations, the species has fallen from 5 to 2.1 million since the 1990s.

In the 1980s, the Quebec-based George River herd, the largest herd in North America at the time, numbered around one million; recent estimates put the herd at 5,500. It was a dramatic collapse for one of the mightiest herds of any species worldwide.

With the disappearance of the South Selkirk and South Purcell herds, the southern extension of mountain caribou has been erased and the remainder moved up approximately 100 miles north into Canada.  

Both woodland and barren-ground caribou remain threatened throughout all their ranges, and extinction looms without drastic change in human behavior.

Libby Ehlers, another Ph.D. candidate in wildlife biology at UM who studied wolves and caribou for over a decade, said both subspecies do not handle human impact well — they avoid it like they would predators. 


Ehlers and her son, Bechler, prepare their drone for flight. Drone imaging was used to gather imagery of fire disturbance and lichen coverage around the Fortymile herd range.

Over the last 100 years, humans have continued to encroach deeper into old-growth forests, threatening most corners of habitat for a species that has evolved over millions of years.

Extirpation, or local extinction, has steadily occurred for over a decade throughout the Lower 48, British Columbia and Alberta. Twelve herds in British Columbia have less than 25 individuals roaming their home ranges fractured by the combination of forestry, oil and gas development and mining. Ehlers studied five herds during her masters research in British Columbia. One, the Burnt Pine herd, went extinct during her research. Thirty of British Columbia’s 52 herds are at risk of extirpation.

“Woodland caribou are in massive decline due to human development,” she said.

During the winter, caribou exclusively use the spongy vegetation lichen as a food source. It is vital to their survival. Caribou feed on two primary types of lichen, terrestrial and arboreal. Barren-ground mostly eat terrestrial, while woodland populations eat both. Lichen provides caribou the opportunity to live where many other ungulates cannot.

“Ecologically, caribou eat something that’s basically worthless,” said Mark Hebblewhite, a professor of wildlife ecology at UM, who studies ungulates and their predators around the world. “In the winter, it’s like living on styrofoam and Gatorade. How do they do it? They occupy this niche in ecosystems that nobody else wants.”

For woodland caribou, following the growth of lichen gave them the spatial separation to avoid predators altogether. Human impact, and changes in climate, threaten this critical food source.

Hebblewhite, who also advises Palm and Ehlers, observed the decline of caribou over the last 25 years throughout the northern landscapes. In the early 2000s, Hebblewhite worked with wolves in Banff National Park. One of his hobbies involved backpacking around the park to find woodland caribou. In 2009, the Banff herd had dwindled down to five individuals before an avalanche killed the remainder of the herd. He never saw a caribou in the park. 

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Family Business

Libby Ehlers was one-month pregnant when she chased down calves from the Fortymile herd in 2018.

In August, when she was five months pregnant, she and her family flew into Tok, a small town near the herd’s range. Her husband, Nick, and son, Bechler, spent the month with Libby researching caribou as a family. For five days, the family took a helicopter to four different sites in the Alaskan backcountry.

“It was an amazing experience to be able to do this with my family,” said Ehlers, who acknowledges this wouldn’t have been possible without the support of many people around her. “We were trying to go to as many sites as we could to collect plants in high use caribou areas.”


Wildlife biologist Libby Ehlers, 40, with her children Taela, 1, and Bechler, 5, hold up a scrapbook with photos of their time in Alaska and the Yukon territory. Ehlers did field research on herds of caribou there, while pregnant with Taela, along with her husband, Nick, and Bechler, then 3 years old.

After the backcountry, the family took a camper around as much of the caribou habitat as they could access with roads. Nick and Bechler helped with drone flying, plant measurements and plant and stool collection. The 3-year-old became pretty good at identifying lichen by the end of the month.

“There are fundamental field ecologists and biologists who have brought their families into the field,” Ehlers said. “This is part of the reason I took on this project, to experience the North and to research together as a family.”

Though the Fortymile herd is better off than most, changes in fire severity and precipitation impact how the species lives and moves through their home range. Ehlers estimates the Fortymile herd could be nearing its carrying capacity, threatened by less food availability from overuse and fire effects on their food sources. Climate change makes things worse.

“The rain-on-snow events that are starting to happen in the North is a big problem,” Ehlers said. 


Bechler Ehlers, 5, flips through his family's scrapbook that has photographs of their adventures when researching caribou herds in the Yukon territories. Ehlers was 3.5 years old when he joined his mother and father as they tracked herds of caribou.

Unlike every other ungulate species, both male and female caribou grow antlers. Using a combination of antlers, hooves and snouts, caribou crater down into the snow to hunt for lichen, their winter food source. Increasing freeze and thaw cycles make it difficult for caribou, as well as other species that rely on digging, to reach their winter meals. 

Ehlers said these types of climate-driven impacts might affect whether populations survive or not.

Population collapse has happened before. The Fortymile herd plummeted to around 5,000 animals in the 1960s because of overhunting and predation effects. Scientists worry it may happen again, but not just from top-down pressures like overhunting and predators. Bottom-up pressures, such as fire severity affecting lichen availability or rain on snow events, are changing earth under their hooves.

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The Predators

Ehlers studied wolves before caribou in Yellowstone and British Columbia. Wolves have become central to the conversation around caribou conservation in Western Canada.

Predators and caribou lived in balance for thousands of years, but the predator-prey dynamics of the region changed in the past century. Woodland caribou have felt the brunt of this effect.


A lone wolf travels through Jasper National Park. Thousands of wolves have been culled in Western Canada to protect caribou populations from increased predation.

The accumulated effects of industry on the landscape have fractured habitat throughout the continent. Seismic lines, narrow corridors used to transport and deploy survey equipment, turn forests into corn-mazes. Roads and highways disconnected wildlife corridors. Large scale clearcutting by industry businesses disrupted old-growth forests.

As industry presence expanded, the forests that provided woodland caribou the spatial separation from other ungulates and predators were lost. Industry exploration and development grew, replacing old-growth forests with young vegetation. Moose and deer thrive in this habitat, and they began foraging areas avoided for thousands of years. Predators were right behind them.

Compounding issues have made it impossible for woodland caribou to survive on their own. Thousands of wolves have been killed throughout British Columbia and Alberta to save caribou, a move scientists agree is necessary for caribou to survive.

“If the province of British Columbia stopped killing wolves, they would guarantee the extinction of half of the province’s caribou herds,” Hebblewhite said.

Until the destruction of their historical ranges, wolves, bears, cougars and wolverines would undoubtedly kill the occasional woodland caribou, but focused on ungulates with higher returns, such as moose or deer. Caribou were considered secondary-prey options.

Hebblewhite said it likely wouldn’t be uncommon for woodland caribou herds to go entire winters without seeing a wolf. Their ability to travel through deep snow and densely wooded peatlands was their defense. Separation afforded them safety. But without the separation, caribou cannot keep up with increased predation.

Most female caribou cannot give birth until their third year, and like humans, most only have one calf each year. For comparison, mule deer can reproduce after 18 months, usually birthing twins. Birth rates for woodland caribou never needed to be high, because they evolved to avoid predators and larger numbers would make their herds more noticeable.

Moreover, when wolf populations in the United States and Canada dropped in the 1960s, ungulates flourished throughout the region. Though hunters might have loved these increased populations, ecosystems became extremely unbalanced. Deer and moose numbers exploded, and wolf numbers followed as they naturally repopulated areas around Banff and Jasper national parks in the 1980s, eventually making their way back to the Lower 48.

Combine increased wolf numbers with a fractured landscape and you get the problem facing the region today, an influx of primary-prey species and proliferating wolf populations.

“It’s tragic if we are killing wolves and not protecting habitat,” said Jodi Hilty, president and chief scientist for the Yellowstone to Yukon Conservation Initiative, which aims to connect and protect habitat between the U.S. and Canada. “Wolves aren’t endangered, caribou are endangered. But we can only support the culling of wolves if the government gets serious about conserving and protecting habitat.”

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The Economics of Conservation

Over the last century, the rural economies of Canada and the U.S. grew to rely on forestry, mining and other industries. Protecting caribou has put the provincial and federal governments of Canada in a bind. 

The Canadian authorities have failed to enforce protection of critical habitat under the Species at Risk Act, fearing caribou conservation might crumble certain parts of the economy. 

“The Endangered Species Act was written in 1969, and revised in 1972. It’s had almost 50 years of testing, prodding, case studies. In Canada, our Species at Risk Act was written in 2002,” said Hebblewhite, who grew up in Ontario. “By the time the first recovery plan for caribou came out in 2012, we’re not even a decade old.”

Hebblewhite said SARA lacks the bite the ESA might have to protect species, and Mountain caribou protection is happening too slowly for many herds. The disappearance of the South Selkirk herd represents the first large mammal species to go extinct in the U.S. since the passing of the Endangered Species Act of 1973. 

“You might remember seeing those bumper stickers, ‘Save a logger, eat an owl.’ Caribou and the spotted owl are very similar. They are both very controversial issues,” Hebblewhite said. He said the parallels between spotted owls and caribou are similar both ecologically and politically. 

The spotted owl controversy of the late ‘80s into early ‘90s inflamed the conversation around endangered species in the U.S. and remains one of the ESA’s largest test cases. Endangered Species Act enforcement threatened the  forestry industry that employed many throughout the Pacific Northwest. A similar scene is playing out in Canada today.

Oil and gas development, forestry, mining and agriculture highlight the industry presence in the region. In Alberta, oil and gas account for 30% of the economy, according to the Canadian Association of Petroleum Producers. Mineral, solid wood, pulp, paper and energy products account for 70% of exported goods and commodities from British Columbia, according to the province. Recreational activities, such as snowmobiling and heli-skiing operations, place further stress on the sensitive species.

Provinces currently oversee caribou recovery, which is notably failing. Enforcing SARA would pave the way for the federal government to intervene and control caribou recovery. Large scale recovery of a species at this scale has never been done in Canada, and time is running out.

“Even if we stopped all impact today, it would take 40 to 60 years for the land to return to its natural state to positively impact caribou,” Hebblewhite said. “Half of the herds would go extinct by then.”

The species that decorates the Canadian quarter is proving to be the ultimate conservation test for the federal and provincial governments of Canada.

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The Way Forward

The South Selkirk herd was designated under the ESA in 1984 and teetered with extinction for over 30 years before they finally disappeared in early 2019. Ten months later, the U.S. Fish and Wildlife Service strengthened protection for the extinct herd by placing all southern mountain caribou herds on the endangered species list.

In the Nov. 1 ruling, USFW said, “… (the) loss of the southern mountain caribou population would result in the loss of the only remaining population of the woodland caribou in the coterminous United States.”

The ruling acknowledges the COSEWIC designations of different types of mountain caribou, a first in U.S.-Canadian caribou partnership. It also increases pressure on Canada to place the remaining 15 southern mountain herds on their endangered list. In Canada, southern mountain caribou are listed as threatened, not endangered. Its federal government has ignored COSEWIC recommendations for upgrading the herds. However, USFW rulings come a little too late for the Selkirk and Purcell herds.


A caribou cow from the Kennedy-Siding herd, last estimated to have around 80 individuals, moves through an experimental feeding site in its range. First Nations and scientists implemented the feeding program to encourage herd recovery, one of the many steps being taken throughout the region.

Hebblewhite said it is unlikely caribou will ever return to the continental United States because there just isn’t enough protected habitat for true recovery.

Indigenous communities from Washington to Alberta to Alaska to Quebec revere caribou, a species integral to cultures throughout North America. Across  Canada, many First Nations and non-treaty groups have given up their rights to harvest caribou.

Lacking government protection of habitat forced Indigenous groups and conservation groups to take ownership of their local caribou herds. Everything that can be done without habitat protection is being attempted: maternity penning, translocation of caribou to new herds, highway patrols during migration seasons, feeding programs and hunting moratoriums. Yet, none of these address the root issue of habitat loss. Like wolf control, these efforts are Band-Aid solutions.

“Many First Nations are charging forward to recover caribou on their own,” said Hilty, whose conservation group is involved in protecting caribou throughout British Columbia into the U.S.

Palm, Ehlers and Hebblewhite agree that  proper management and habitat protection will be necessary to save herds. They also acknowledge the true effects of climate change on the species remain unknown.

In the Arctic National Wildlife Refuge, Indigenous and conservation groups have battled oil and gas interests for decades over drilling access. The refuge is home to the Porcupine herd, one of the largest remaining herds in North America. In 2017, the Trump administration and Congress worked to legalize oil drilling in the refuge. This would lead to increased human impact in the region, the same issue that has led to decline and disappearance of the herds throughout the continent.

Hebblewhite said the opening of the Alaskan refuge for new drilling would highlight how we have not learned lessons from what the U.S. lost in bison or woodland caribou.

“I can talk all hopeful that maybe one day we’ll get the ecosystem right, but somehow I doubt it,” he said. “We’re out of time for a lot of herds.”