Wolf reduction boosts caribou survival—but only in rugged terrain

 Reducing wolves to protect endangered caribou doesn't always deliver the expected results—and the shape of the land may be the deciding factor.

That’s according to research led by doctoral student Tazarve Gharajehdaghipour and professor Dr. Cole Burton in UBC's faculty of forestry and environmental stewardship, which examined newborn caribou survival in Itcha Ilgachuz Park in west-central B.C.

Using GPS collars to track animals, the team found that B.C. wolf removals boosted calf survival in steep, mountainous terrain, but made no difference in flatter terrain.

"This study is a note of caution," said Dr. Burton. "Different herds face different conditions. Wolf control may not be reducing calf mortality as effectively as we once thought."

How land and predators affect calf survival

The key factor is which predators can catch calves at different ages. Bears and wolverines hunt newborn calves in the first two weeks, but can’t catch older, more mobile calves. Wolves, by contrast, can catch the older, faster calves.

In rugged areas, this makes a big difference. Bears and wolverines can kill newborns at high elevations, but by the time mother-calf pairs move down to valleys at around three weeks old, the calves are too fast to catch. At this stage, wolves become the main threat.

Before wolves were removed, most calf deaths occurred during this period. Removing wolves eliminated this later cause of death, boosting survival by 41 percentage points—because bears and wolverines cannot hunt the older calves effectively.

In more accessible areas, wolves can reach calving sites throughout the season, including early when calves are young and vulnerable. When wolves were removed, other predators, such as bears and wolverines, simply killed more of these young calves, so overall survival did not improve.

Tracking calves through mothers’ movements

This is the first study to use GPS collars to follow newborn mountain caribou survival. The research builds on tracking methods developed by co-author Dr. Marie Auger-Méthé, a UBC associate professor in the Institute for the Oceans and Fisheries and department of statistics.

They found clear patterns: mothers abruptly start moving less when giving birth to stay close to newborns, then gradually increase activity as calves get stronger, or quickly return to normal movement if a calf dies.

"This method lets us watch the critical first four weeks of life, when calves are most at risk. We also used camera traps to see when predators were on the calving grounds," said Gharajehdaghipour.

The caribou collar data, which this research paper is primarily based on, was collected by B.C. government biologists, and secured through open access. 

Conservation beyond predator control

The research also found that calf deaths before wolf reduction—likely caused by wolves—were linked to horseback and ATV trails and treed valleys. This suggests wolves use these areas to reach calves. Limiting trail development could help reduce wolf-caused deaths in places where wolf control isn’t used.

While B.C.'s wolf reduction program now covers 15 caribou herds, Dr. Burton emphasizes it’s critical to protect habitat.

"If wolf control is sometimes ineffective and diverts attention from habitat restoration, it's a real concern," he said. "Without recovering habitat, you'd have to keep controlling wolves indefinitely."

The researchers recommend that wildlife managers consider the landscape, predator communities, and habitat conditions before starting wolf control programs. They also encourage using GPS tracking and camera traps to better understand calf survival across B.C.

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Journal

The Journal of Wildlife Management

DOI

10.1002/jwmg.70143 

Pumas putting Patagonian Penguins at risk

 Summary:

• Some Argentinian penguins are experiencing high levels of predation from pumas recolonising their historical territory. A new study has quantified the risk on long-term penguin population survival.

• Over four years, pumas at a national park on the Argentinian Patagonia coast are thought to have killed over 7,000 adult penguins (7.6% of the colony’s adult population) – but left many uneaten.
• Long-term, however, puma predation alone is unlikely to threaten colony viability, while low breeding success and reduced juvenile survival appear to be greater threats to the survival of these penguins.
• The findings have been published today (5 February) in the Journal for Nature Conservation.

 

Should we protect an emblematic species if it may come at the cost of another one – particularly in ecosystems that are still recovering from human impacts? This is the conservation dilemma facing Monte Leon National Park, on the Patagonian coast in Argentina.

Since cattle ranching was abandoned in southern Argentina in 1990, pumas (Puma concolor) have been recolonising their historical ranges in this area. For the first time, this brought them in contact with Magellanic penguins (Spheniscus magellanicus) who had moved to the mainland from nearby islands due to the absence of terrestrial predators. Being largely defenceless, the penguins became an easy target for the large carnivore – but it was unknown up to now the exact impact the pumas were having on penguin population numbers.

Since its creation in 2004, researchers from the Centro de Investigaciones de Puerto Deseado of the Universidad Nacional de la Patagonia Austral and rangers from the Monte Leon National Park have monitored the penguin populations in the Park. Over four years (2007-2010), they counted the number of carcasses caused by puma predation. In the new study, they collaborated with researchers from Oxford University’s Wildlife Conservation Research Unit (WildCRU) to analyse the data.

Based on the numbers of penguins found killed, the research team estimated that more than 7,000 adult penguins were killed over the four-year study, most of which were not fully eaten, indicating that not all the penguins were killed for food. This is roughly 7.6% of the adult population (around 93,000 individuals).

Lead author Melisa Lera, a postgraduate student at WildCRU, Oxford University said: “The number of carcasses showing signs of predation we found in the colony is overwhelming, and the fact that they were left uneaten means pumas were killing more penguins than they required for food. This is consistent with what ecologists describe as ‘surplus killing’. It is comparable to what is seen in domestic cats when prey are abundant and/or vulnerable: ease of capture can lead to cats hunting more birds, even when they do not end up actually eating them. We needed to understand if the penguin colony’s persistence could be threatened due to this behaviour.”

However, when the team carried out modelling on the data, this indicated that pumas alone were unlikely to drive the colony at Monte León Park to extinction. Instead, the colony’s future appears to be far more sensitive to factors such as reproductive success and juvenile survival. Population extinction was projected only under hypothetical scenarios combining low juvenile survival (with around 20% failing to reach adulthood) and very low reproductive output (a maximum of one chick per pair). High puma predation was predicted to exacerbate these outcomes.

Study co-author Dr Jorgelina Marino (WildCRU, Oxford University) said: “This study captures an emerging conservation challenge, where recovering carnivores are encountering novel prey. Understanding how these dietary shifts affect both predators and prey is essential to inform conservation.”

Since the models identified breeding success and mortality of the juveniles as some of the key determinants of population viability, the authors highlight the need to understand how environmental factors such as nutrients, food and temperature - known to be influenced by climate change - may affect the penguins’ reproductive success.

As terrestrial predators continue to expand into coastal environments, further mainland colonies of seabirds and other coastal species may become vulnerable. For instance, non-native feral hogs are now key predators of loggerhead sea turtle eggs along the Georgia coast, USA, whilst coyotes in eastern North America are colonising coastal barrier islands, with impacts across these ecosystems.

The authors emphasise the need for sustained monitoring to detect demographic declines early and to guide management actions to prevent severe ecological consequences. The Park authorities continue to monitor Puma and Penguin populations.

The mere smell of predators is enough to change deer behavior

New research shows that the mere smell of predators is enough to change deer behavior and limit browsing damage to tree saplings. The findings offer a potential tool for forest recovery and highlight the important role large predators play. The research is published in the British Ecological Society’s Journal of Applied Ecology.

Research conducted in the forests of south-eastern Germany, shows that the smell of large predators, like lynx and wolves, is enough to make deer more cautious and spend less time eating tree saplings.

In an experiment that involved adding lynx and wolf urine and scat to plots of saplings, researchers from the University of Freiburg found that plots with the scent of predators, particularly lynx, had less browsing damage to young trees than control plots. Deer visited predator-scented plots less and spent less time foraging when they were there.

Over browsing from deer is a major threat to forest regeneration, damaging biodiversity and causing economic losses for the forestry sector. Mitigating browsing damage usually involves substantial human effort and financial resources.

Walter Di Nicola, one of the lead researchers, said: “At a time when debates around large carnivore conservation often focus on conflicts, our study highlights the benefits these species bring to landscapes. The presence of carnivores, even just their scent, could help reduce the ecological and economic problems associated with browsing from overabundant deer populations.”

The research was conducted in forests where both lynx and wolves have been reintroduced. But the researchers say they would expect similar effects in countries like the UK where these predators have long been absent.

Walter said: “In the UK we would expect similar but probably weaker effects. Deer still have some innate fear of predators, even if those predators have been absent for generations. Where predators return, we expect these responses – and their ecological benefits – to become stronger over time.”

The researchers call for conservation strategies that promote large carnivores in forests as a natural, low-intervention solution to over browsing.

To test the effects of large carnivore smells on deer behavior, the researchers set up experimental plots at 11 locations around the forests. Each location comprised of four plots marked with the scent of wolf, lynx, cow and water (as a control). In each plot 30 saplings were planted.

The researchers regularly monitored the saplings to assess browsing damage and used camera traps to record red and roe deer behavior, such as how long and how frequently they visited each plot.

The researchers found that there was a stronger response to the smell of lynx compared to wolf. They believe this could be due to the ambush hunting strategies of lynx, which tend to stalk their prey from close distances, meaning deer might perceive lynx scent cues as more of a threat.

They also point out that wolves were establishing themselves in the area at the time of the experiment, and the deer had much more experience of the threat of lynx.

The researchers caution that their experiment cannot fully replicate the complexity of natural-predator prey interactions. In their set up they used concentrated predator scents, which were easier for deer to detect than in natural conditions. In the wild, real predator cues are more scattered and unpredictable.

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Journal

Journal of Applied Ecology

DOI

10.1111/1365-2664.70267 

Changes to cougar diets and behaviors reduce their competition with wolves in Yellowstone

A new study shows that interactions between wolves and cougars in Yellowstone National Park are driven by wolves stealing prey killed by cougars and that shifts in cougar diets to smaller prey help them avoid wolf encounters.

The study, published at a time of growing overlap between cougar and wolf habitats in the western United States, found wolves occasionally killed cougars, but cougars did not kill wolves.

Researchers also found that cougars tend to avoid areas where wolves have made kills and stay close to escape terrain, such as climbable trees. Cougars responded to a decline in elk in the park by killing more deer, which they consume faster, leading to fewer interactions with wolves.

Published this week in PNAS, the study draws on nine years of GPS data from collared wolves and cougars and field investigations of nearly 4,000 potential wolf or cougar kills in Yellowstone. The findings suggest that coexistence between wolves and cougars depends less on overall prey abundance and more on prey diversity and the availability of escape terrain.

“In North America and worldwide, carnivore communities are undergoing major changes,” said Wesley Binder, a doctoral student at Oregon State University and lead author of the study. “Our research provides insight into how two apex predators compete, which informs recovery efforts.”

For much of the 20th century, government policies in the United States nearly eradicated both wolves and cougars. Cougar populations began to rebound in the 1960s and 1970s in the U.S. under protection. Wolf reintroduction started in 1995, including in Yellowstone. Both species are now recolonizing much of the western U.S.

“You've had these places that in the last 20, 30 years have had cougars come back, and now wolves are coming back as well,” Binder said. “There are a lot of people asking questions like, ‘What are our ecological communities going to look like now that we have both of these large carnivores back on the landscape?’”

Binder began his doctorate at Oregon State in 2022 after nearly a decade working on cougar monitoring in Yellowstone as part of the Yellowstone Cougar Project. His work included setting up a system of 140 remote cameras in the northern part of the park and catching and collaring cats.

The new study builds on decades of research showing that wolves dominate interactions because they live in packs, while cougars are solitary. Previous studies have demonstrated how subordinate carnivores exhibit a tradeoff with dominant carnivores; they suffer mortalities but also benefit from scavenging their kills. Yet cougars seldom scavenge other carnivore kills and are instead efficient hunters themselves, leading to unclear principles that govern their interactions with wolves.

Findings from the new paper provide some answers:

• Researchers investigated 3,929 potential wolf and cougar kill sites: 852 were wolf feeding events, and 520 were cougar feeding events.
  • Wolves made 716 kills and scavenged 136 times, primarily on elk (542), bison (201) and deer (90).
  • Cougars made 513 kills and scavenged seven times, mainly on elk (272) and deer (220).
• Comparing data from 1998-2005 and 2016-2024 revealed major shifts:
  • For wolves, bison increased from 1% to 10%, and elk declined from 95% to 63%.
  • For cougars, elk dropped from 80% to 52%, and deer increased from 15% to 42%.

These kill site investigations were then used to train machine learning models that used GPS data to predict wolf and cougar kill sites. This allowed researchers to pair all wolf and cougar movements with probable kill sites and identify the drivers of their interactions. They found wolf-cougar interactions were highly asymmetric: 42% occurred at predicted sites where cougars killed prey, and only one happened at a site where a wolf killed prey.

The researchers documented 12 adult cougar deaths from 2016-24, two of which were caused by wolves. In both events, no escape terrain was available, and the wolves didn’t consume the cougars but ate the elk the cats had killed. They recorded 90 wolf deaths during the same period, none of which were attributed to cougars. Most were due to natural causes or human actions.

Co-authors of the paper are Joel S. Ruprecht, Rebecca Hutchinson and Taal Levi of Oregon State’s College of Agricultural Sciences; Jack Rabe of the University of Minnesota and Yellowstone Center for Resources; and Matthew Metz and Daniel Stahler of Yellowstone Center for Resources. Hutchinson is also part of Oregon State’s College of Engineering.

 

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Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2511397123 

Indigenous-led hunting most effective for tackling deer overabundance

As ecosystems in coastal British Columbia disappear due to long-term browsing pressures from overabundant black-tailed deer, a new study led by UBC with Coast Salish Nations and regional research partners identifies the most effective solutions to address deer overabundance on the Southern Gulf Islands.

The research, published in People and Nature, finds Indigenous-led hunting to be the most successful and cost-effective strategy for managing hyperabundant deer when considering ecological and cultural needs. Drawing on both Indigenous and Western knowledge systems, the study also highlights the importance of honoring distinct knowledge and value systems equitably in wildlife management.

A growing ecological crisis

Following almost two decades of research led by Dr. Tara Martin from UBC’s Faculty of Forestry, black-tailed deer populations on the Southern Gulf Islands are now estimated to be up to 10 times higher than they were a century ago, due to a combination of human-altered landscapes, restrictions on hunting, and the eradication of predators.

As deer populations grow unchecked, they overbrowse vegetation, prevent forests from regenerating, reduce biodiversity, and disrupt cultural connections to the land.

“For most people these islands look beautiful and natural, but they are entirely degraded,” says Dr. Martin. “The change has been so slow, most people don’t recognize this shift. We’ve found hyperabundant deer are one of the major drivers of this change.”

The consequences are stark. One of B.C.’s most endangered ecosystems, the Garry Oak meadow, is now at risk of irreversible collapse due to overgrazing. Other regions across Canada and the globe are facing similar threats from hyperabundant herbivores including Haida Gwaii, Ontario, Australia, New Zealand and New Caledonia.

Inclusive approach to decision-making

Developing deer management strategies that address overpopulation and also support the well-being of people and the land—rather than focusing solely on ecology—is inherently complex.

“This study offers a roadmap to help unpack complicated problems where many values and goals compete, often leading to decision paralysis and inaction” says lead author and doctoral student Sofie McComb. “Hyperabundant deer are damaging ecosystems around the world, and we’re offering a framework that gives decision-makers practical, inclusive solutions.”

Working in collaboration with Coast Salish Nations and local land stewards and knowledge holders, Dr. Martin’s group considered a number of strategies for successful deer management. These included Indigenous-led hunting, improving predator viability, hiring deer reduction specialists, using birth control, increasing licensed hunting, and combining approaches.

Indigenous-led hunting was the only strategy with a high likelihood of being successful and achieving ecological and cultural benefits. Compared to the status quo, Indigenous-led hunting was found to increase the likelihood of maximizing human and ecological wellbeing by almost 60 per cent, and was more than 50 per cent likely to maximize project uptake and implementation goals.

Strategies such as increased licensed hunting were cost-effective from a Western science perspective, as they are low-cost strategies with moderate feasibility, but were less likely to achieve meaningful long-term benefits (less than 30 per cent likelihood).

Cost of inaction

Experts agreed that sticking with the status quo will not improve ecosystem functions and will continue to feed the decision-making paralysis fuelled by a fear of controversy. Researchers warn that delaying action is the most harmful option.

“If we don’t do something soon, the ecosystems will not be recoverable, because there will be nothing left” says Sofie McComb. “The deer are also struggling, and have turned to eating starvation foods. Inaction is action – that is the action that has been chosen and the ecosystem is suffering.”

The study provides an inclusive, transparent framework for communities worldwide facing hyperabundant herbivores. By integrating multiple knowledge systems and weighing feasibility and cost alongside ecological and cultural benefits, decision-makers can chart a path toward recovery that is both effective and socially grounded.

“It’s possible to find solutions to complex environmental issues that are good for people, the land and the deer” says Dr. Martin. “This work shows that restoring cultural sovereignty and ecosystem health can go hand in hand.”

Please contact charlotte.fisher@ubc.ca or lou.bosshart@ubc.ca to arrange interviews with Dr. Tara Martin or Sofie McComb.

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Journal

People and Nature

DOI

10.1002/pan3.70136 

 

What happens to ecosystems when you restore iconic top predators?

 

 It’s more complicated than you might think.

Across North America, mountain lions, bears, and gray wolves have made a remarkable comeback over the last 50 years. Once nearly exterminated, these animals have been recovering their populations and returning to the landscapes they historically roamed, thanks to protections like the Endangered Species Act, hunting limits, and reintroduction programs.

The ecological impact of restoring these large carnivores is potentially huge, in part because of the way they could help to balance ecosystems by keeping prey populations under control.   

One famous example is a study from Yellowstone National Park in the early 2000s, which seemed to indicate that the restoration of gray wolves helped forests recover by scaring elk away from habitats where they might otherwise eat vulnerable tree saplings. The study garnered a frenzy of international media attention as an illustration of an ecology concept called “trophic cascade,” where the introduction or removal of an animal at one level of the food chain creates a series of effects throughout.  

However, further research in Yellowstone National Park and elsewhere has since presented a murkier picture of whether, when, and how such impacts have occurred to-date across North America. UC Santa Cruz Professor Chris Wilmers, a wildlife ecologist who studies large carnivores, has been contributing to and carefully tracking these developments. 

“The Yellowstone trophic cascade example has really been oversimplified in the media,” he said. “The scientific evidence today shows that there are many factors at play, so the effects we’re seeing can’t neatly be attributed solely to the reintroduction of wolves. That’s important to understand because, if the goal of large carnivore restoration in other parts of the world is to initiate a trophic cascade, it’s going to be a lot more complicated than what people might expect.”

To help address the issue, Wilmers wanted to get to the bottom of what we can confidently say about the ecological impacts of large carnivores in North America at this stage in their recovery and what further research and clarification is still needed. So he led a team of scientists in developing a new paper that analyzes findings of more than 170 studies from the 1940s to the modern era. This comprehensive approach allowed the team to evaluate the weight of evidence in a way that can help to guide the future direction of both research and wildlife management.

Dynamics between predators and prey

One clear trend that emerged from the team’s research is that there are often more important forces at play in North American ecosystems than the dynamics between wolves, bears, and mountain lions and their preferred prey. 

Human impacts like hunting and land-use changes ultimately have a much greater impact than large carnivores on the population size, distribution, and behaviors of animals like deer, elk, and moose. Environmental constraints related to habitat and food are also more influential in limiting population size for these prey animals than predation.

That’s not to say that large carnivores can’t still meaningfully control populations of prey species. But those effects are more likely under a very specific set of conditions. For example, predators have more impact in spatially constrained systems, like islands, where their prey have nowhere else to go, and in instances where multiple predators are targeting the same species at different life stages.

A prey species is also more vulnerable to population impacts when it’s competing with another more resilient species. That’s because a growing population of a competitor species, often due to human-caused habitat changes, can elevate predator populations in a way that reduces the prey species not being bolstered by population growth. Population reductions of bighorn sheep and mountain caribou in Western Canada are a few examples of this effect. 

Large predators also seem to suppress populations of smaller carnivores across North America by about 18% on average, according to a correlational analysis of species abundance conducted in the new paper. Those impacts can sometimes help traditional prey animals or other small carnivores. For example, pronghorns and red foxes have benefited from population reductions of coyotes, following the recovery of larger carnivores. 

Broader ecosystem impacts

How these impacts ripple down to the very bottom rungs of the food chain is a bit less clear. But long-term research in Yellowstone National Park and a handful of other systems has helped build consensus around what key mechanisms are necessary for a true trophic cascade. In situations where browsing and grazing is suppressing plant growth, predators can have an indirect positive effect on plants if their presence reduces plant-eating by other animals.

Research shows that even the fear of large predators changes prey behavior, and this could theoretically reduce pressure on plants in some cases. But, in practice, evidence for behaviorally mediated trophic cascades has been inconsistent. So trophic cascades are more likely to be observed in situations where predators are truly limiting prey populations. Tailoring future research to these specific situations could help illuminate the process. 

In Yellowstone National Park, large carnivore recovery has certainly triggered some ecological changes that are consistent with a trophic cascade. But key mysteries remain. Initial behavioral theories about what types of habitats elk would avoid in response to fear of wolves and how this might affect their access to browse on woody plants have not been supported by later studies. And it remains unclear to what extent observed elk population declines can be attributed specifically to wolves versus other predators, competitors, or environmental factors like drought.

Ecosystem recovery in the park also seems to be limited by a number of factors. Research across North America has shed new light on certain conditions that can dampen the effect of a trophic cascade. When multiple prey animals eat the same plants, but one is less vulnerable to predation, trophic cascade may be masked. For example, both bison and elk eat tree saplings in Yellowstone, but adult bison are too large for predators like wolves to take down, so grazing and browsing pressure from bison has remained largely unchecked. 

The ability of plant communities to recover can also be limited by changes in underlying environmental conditions that have occurred since predators were first removed from an ecosystem. In Yellowstone, the loss of both wolves and beavers changed the park’s hydrology so much that rivers became narrower over time with steeper banks, reducing suitable habitat for key tree species today. 

Lessons for wildlife conservation

Overall, the new paper demonstrates how efforts to draw cause and effect connections between a particular large carnivore and ecosystem recovery are often obscured by complex interactions among and between different species of predators and prey, how they move and behave across landscapes, and how humans are transforming these systems. But that doesn’t mean restoration efforts for mountain lions, bears, and wolves aren’t ecologically beneficial. 

“Restoring predators certainly will add to biodiversity and to the complexity of how your ecosystem works, and that is a good thing,” Wilmers explained. “It’s just that it’s not going to have a simple effect that you can easily predict before restoring these species.”

Rapidly improving technologies such as GPS telemetry, genetic sampling, camera traps, and bioacoustic monitoring may get us closer to understanding and predicting impacts in the near future, by enabling better tracking of predator and prey populations and their interactions. 

In the meantime, though, the very fact that so much uncertainty remains about how best to restore the ecosystem functions of large predators is strong evidence of the need to protect threatened species before they disappear. 

“One of the things the research points to most clearly now is that you want to avoid losing these species of large carnivores from systems in the first place,” Wilmers said. “Because putting them back, while useful to do, could take 50 to 100 years or more to really restore what was lost.”

Polar bears act as crucial providers for Arctic species

New study shows polar bears annually provide millions of kilograms of food, supporting a vast Arctic scavenger network

Peer-Reviewed Publication

San Diego Zoo Wildlife Alliance

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Two-year-old polar bears with bearded seal carcass and ivory gulls

Image Credit: Wayne Lynch

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Credit: Photo Credit: Wayne Lynch

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SAN DIEGO (Oct. 28, 2025) – A new study published in the scientific journal Oikos reveals for the first time the critical role polar bears play as carrion providers for Arctic species. Researchers from University of Manitoba and San Diego Zoo Wildlife Alliance, alongside researchers from Environment and Climate Change Canada, and the University of Alberta, have estimated that polar bears leave behind approximately 7.6 million kilograms of their prey annually, creating a massive and vital food source for a wide network of arctic scavenger species. 

This research demonstrates that these apex predators are a crucial link between the marine and terrestrial ecosystems. By hunting seals on the sea ice and abandoning the remains, polar bears transfer a substantial amount of energy from the ocean to the ice surface, making it accessible to other animals. The study identifies at least 11 vertebrate species known to benefit from this carrion, including Arctic foxes and ravens, with an additional eight potential scavenger species. 

“Our findings quantify for the first time, the sheer scale of polar bears as a food provider to other species and the interconnectedness of their ecosystem,” says Holly Gamblin, lead author of the study and PhD Candidate in the Department of Biological Sciences at the University of Manitoba. “What is apparent from this review is that there is no other species that adequately replaces how a polar bear hunts, in which they drag their prey from the water to the sea ice and leave substantial remains for other species to access.” 

Past research has emphasized that continued warming in the Arctic and the resulting loss of sea ice directly endanger polar bear populations. However, this new research highlights that a decline in polar bears would not only impact the species itself but the loss of the carrion they provide could have significant consequences for the entire Arctic ecosystem. 

“Our research highlights the important role of polar bears as carrion providers,” says Dr. Nicholas Pilfold, Scientist in Population Sustainability at San Diego Zoo Wildlife Alliance. “The sea ice acts as a platform for many species to access scavenging resources provided by polar bears, and ultimately, declines in sea ice will reduce access to this energy source. Our findings indicate that documented declines in polar bear abundance in two subpopulations have already resulted in the loss of more than 300 tonnes of food resources for scavengers annually.” 

These findings highlight the interdependence of arctic wildlife species and their shared vulnerabilities in the face of rapid environmental change. With polar bear populations continuing to decline, this research underscores the urgency of conservation efforts to protect them, not only for their own sake but for the species that rely on them.