Frequently Asked Questions
Here, you’ll find the answers to frequently asked questions about polar bears, climate warming, and more.
Polar bears are listed under a variety of classifications depending on international, national, and regional regulations. Internationally, they are listed as a vulnerable species by the IUCN. In Russia, polar bears are classified as a Red Data Book species, a listing that includes animals considered rare or endangered. In the U.S., polar bears are listed as a threatened species under the Endangered Species Act. Canada considers polar bears a species of special concern under the National Species at Risk Act. On a regional level in Canada, polar bears are listed as threatened in both Manitoba and Ontario under provincial endangered species legislation.
In all cases, the primary conservation concern for polar bears is habitat loss and reduced access to their seal prey due to climate change. Scientists predict that as the Arctic continues to warm, two-thirds of the world's polar bears could disappear within this century. Research also shows that hope remains if action is taken to greatly reduce carbon emissions soon.
While rapid loss of sea ice is the primary threat to the polar bear’s long-term survival, other challenges include pollution, increased commercial and industrial activity in the Arctic, overharvest, disease, and inadequate habitat protection (denning and seasonal resting areas).
At the 2014 meeting of the PBSG, the world's leading polar bear scientists reported that of the 19 subpopulations of polar bears, three were declining, six were stable, and one was increasing. They lacked sufficient data on the status of the remaining nine.
Very big! Adult males normally weigh 350 to more than 600 kilograms (775 to more than 1,300 pounds). Adult females are smaller, normally weighing 150 to 295 kilograms (330 to 650 pounds). Researchers in Canada estimated one male bear at 800 kilograms (1,700 pounds)!
Scientists usually refer to how tall bears are by measuring them at the shoulder when on all fours. Those heights are typically 1-1.5 meters (3.3-5 feet) for adult polar bears. An adult male may reach over three meters (10 feet) when standing on its hind legs.
They're built for it! Polar bears are adapted for the Arctic climate, where winter temperatures can plunge to -45º C (-50º F). Polar bears are insulated by two layers of fur that help keep them warm. When in good body condition, they also have a thick fat layer. In addition, their compact ears and small tail also prevent heat loss. In fact, polar bears have more problems with overheating than they do from the cold—especially when they run.
Polar bear feet are furred and covered with small bumps called papillae to keep them from slipping on ice. Their sense of smell is powerful for detecting seals. And their powerful claws can haul out a 40-90 kg (150-200 lb) seal from the water for dinner.
Sometimes, males can pull even bigger.
Polar bears have evolved to feed on ice seals, specifically seal fat, the highest calorie food source possible. The bears prey on both ringed and bearded seals across their range, but will take other prey when available. Ringed seals, which are smaller, are the most accessible, especially to younger bears and females. Male polar bears also hunt bearded seals, which are much larger. When adult bears are in good shape, they eat only the blubber in order to build up the fat reserves they need to sustain themselves between meals. They leave the carcass for scavengers, such as arctic foxes, ravens, and other bears.
All the other foods that polar bears may eat are less predictable. Most of these foods, with the exception of walrus or whales, don't provide enough calories to sustain the polar bear's massive body size or to build up the bear's own fat reserves.
While short by our standards, polar bears are considered long-lived animals. In the wild, polar bears live an average 15 to 18 years, although biologists have tagged a few bears in their early 30s. In captivity, some long-lived bears reach their mid- to late 30s. Debby, a captive bear in Canada, lived to be 42.
Polar bear cubs are born in snow caves called maternity dens. After feeding heavily in April or May, female bears that have mated dig a den in late October or early November. Most choose den sites in snowdrifts along mountain slopes or hills near the shore. Some dig their dens in snowdrifts on the sea ice, and others in peat along inland riverbanks. The cubs are most often born in December.
Like a big, white rat. At birth, cubs are 30 to 35 centimeters (12 to 14 inches) long and weigh little more than half a kilogram (about one pound). They are blind, toothless, and covered with short, soft fur. They are completely dependent on their mother for warmth and food.
In March or April. During her time in the den, the mother does not eat, drink, or pass waste. Cubs grow rapidly, thanks to the calories in their mother's rich milk, which is about 31% fat when the cubs are born. In their first year of life, cubs are called COYs, which stands for cubs of the year.
Only humans, and on rare occasions, other polar bears. Some scientists hypothesize that food stress is increasing acts of cannibalism, which has historically been a natural, but infrequent event.
Our chief scientist, Dr. Steven Amstrup, responds to frequent questions and clears up myths and misconceptions about polar bears and climate warming.
Not at all. Ninety-seven percent of climate scientists, the experts in their field, have reached a consensus that climate change is real and is human-caused.
We don’t have evidence that such foods could provide enough nutrients to sustain any of the existing populations of polar bears. It’s true that polar bears have evolved to eat seals, but they are opportunistic hunters and if seals are not available because the sea ice is absent, they will eat almost anything—including vegetation, berries, geese, and bird eggs. Unfortunately, few polar bears have been observed eating more nutritious foods like birds or eggs, and those foods are not abundant enough or distributed widely enough to be a population benefit. And plant foods are just not nutritious enough to compensate for lost seals. Much like a human eating a stalk of celery versus a juicy steak, the nutritional benefit is not the same.
No, satellite measurements show that more energy has been coming in from the sun than is escaping back to space. The earth’s heat load, therefore, has continued to increase in step with carbon dioxide caused by burning fossil fuels.
Currently, much of that heat is being absorbed by the world’s oceans. At some point the ocean will release more of that heat into the air, and we will feel a surge of warmth.
Polar bears have never faced periods as warm as we could see in the next 50 years. There have been warmer periods in the past, but they were not only cooler than what we will experience if we don’t reduce carbon dioxide emissions, they were part of natural cycles of warming and cooling. These cycles were driven mainly by the variations in the earth’s orbit around the sun and by events like massive volcanic eruptions. The current warming is not part of a cycle, and there can be no cooling unless humans take action.
The current, human-caused warming is different from anything we have ever faced. It’s important to remember that regular carbon dioxide is used and created by normal life processes, but we have been pumping large amounts of extra carbon dioxide into the air by relying on coal, oil, and natural gas for our energy needs. To stop this rampant build-up of carbon dioxide and save the sea ice that polar bears require, we must rethink and reduce our use of fossil fuels, switching instead to renewable energy sources like wind and solar.
The earth’s temperature can only continue to increase as long as carbon dioxide emissions rise. The earth won’t heat up to some new stable level and then hold steady. Without our action, the planet can only continue to become hotter and hotter, beyond anything polar bears (or humans) have experienced before. When we burn fossil fuels for energy, we add more and more carbon dioxide into the atmosphere. This build-up acts like a blanket, trapping heat that would have otherwise escaped. The key to getting the climate back to functioning the way it should is to get away from fossil fuels for energy altogether and to look for ways to influence decisions outside our own households about where our energy comes from.
We live in this world together. If we work collaboratively and act on climate warming before it gets worse, we all win, and the polar bear will continue to roam the Arctic for generations to come.
We have never had firm numbers on the global population of polar bears. We do know that some polar bear populations, like those that I studied in Alaska for 30 years, were known to have grown after excessive hunting was controlled in the early 1970s. But we only recently have developed estimates of several populations and still have no estimates for others. Regardless of how many bears may have been around at times past, however, as long as temperatures warm and sea ice habitat continues to decline, polar bears ultimately can only decline. Wild polar bears will become extinct unless we take action to reduce greenhouse gas emissions.
Increased interbreeding will not preserve the magnificent life form that is today’s polar bear. It might preserve some polar bear genes in an animal similar to today’s grizzly bear—but that is not what we are after. Scientists have observed a few polar bear-grizzly hybrids in the wild, and genetics studies indicate some interbreeding has occurred for millennia. Regardless, given the rapid pace of current sea ice losses, polar bears will starve out of their present range long before grizzlies swamp their genes.
Definitely not! Together, we can protect polar bears and people by holding civic leaders accountable for reducing our reliance on fossil fuels for energy and strengthening renewable energy approaches.
To build support for transitioning away from fossil fuels, each and every one of us needs to be confident about talking to our friends and family about the urgent need for climate action.
Polar Bear Tracker
The Polar Bear Tracker follows the movements of satellite-collared polar bears in Hudson Bay, Canada. The tracking is part of a long-term research project conducted by our partners at the University of Alberta and Environment and Climate Change Canada.
If you don’t see recent updates, don’t worry! The tracking device may be experiencing technical difficulties due to the harsh Arctic habitat and is offline for now. This is normal and the bear may come back online soon.
The GPS collars allow researchers to track polar bears, helping us learn about their movements in response to sea ice loss caused by climate change. Because polar bears prefer to roam far out on sea ice, where it is dangerous for humans to travel, data from satellite collars gives scientists a rare glimpse into the lives of polar bears, including the habitats they use and the vast distances they travel.
The GPS collar transmits location data to a satellite, from which researchers can then download movement information. The collar’s battery life depends on how often it shares data. To prolong the battery life, the collar typically sends data to the satellite every four hours.
Collars are built with flexible, synthetic material that sheds water and ice and stays flexible in cold temperatures but is strong enough to withstand Arctic marine conditions for at least one year.
Adult males can’t be collared because their necks are as wide as their heads, so the collars slip right off! And juvenile bears grow too quickly to fit with a collar.
We use the term “real-time tracking” because the collar transmits location data to the collection site several times a day. However, we receive the information weekly and deliberately delay publishing the data. We publish 1-3 new locations roughly once a week as available, usually from October to July.
It is difficult to make technology reliable in the Arctic. The Arctic’s harsh and remote environment makes tracking polar bears challenging and costly. The cold weather, freezing salty waters, and bears who like to rub on the sea ice take a toll on the collars. Sometimes collars stop transmitting for a few months or sometimes they power down entirely until they fall off.
Each collar is programmed to last 1-2 years, then automatically fall off using a timer. Some bears have been collared more than once throughout their lives (contributing extremely important data to our understanding of polar bears), but not for longer than two years at one time.
These days, most collars are programmed to last one year or less. If a collar lasts a full 12 months on a polar bear, researchers are pretty happy.
The collars have a release mechanism with an internal clock that researchers can program. Researchers usually set the timer so that the collar will fall off shortly before the batteries are drained, and the collar is no longer transmitting.
Also, the collars are attached with steel nuts and brass bolts that eventually corrode in a saltwater environment, causing the collar to fall off even if the release mechanism fails. Once they fall off, a GPS location allows researchers to find the collar (if in a retrievable spot), download any stored data, refurbish, and send it out again to save money.
The number of collared bears varies according to project goals, the region, how well-funded a project is in a given year, and how successful researchers are in catching adult females. Usually, 5-10 bears are collared in western Hudson Bay each fall.
Right now, collars can provide the longest and most robust datasets for polar bear movements on sea ice. GPS-linked ear tags have been deployed on male polar bears in recent years with some success, but they rarely last longer than 5 or 6 months. We are currently developing and testing new methods of tracking polar bears that can both withstand Arctic conditions and allow scientists to track adult males and juvenile bears, providing critical data on these two key groups. Check out our Burr on Fur project!
Yes! We encourage teachers and students to make use of the Bear Tracker when possible. Our lessons and materials, along with our Tundra Connections webcasts, make for a wonderful way to learn about polar bears in the classroom.
Unfortunately, we are not able to share the actual coordinates of the bears, as the GPS data do not belong to us. Also, the data are currently being used for research projects that have not yet been published, and so are not available to the public at this time.
For publicly available polar bear data, please check out the USGS Polar Bear Research page.
Ask the Experts
Our team answers your burning questions, ideas, and concerns.
“Giving polar bears a place to rest doesn't solve their main problem, which is finding food if there is no sea ice."
Many people have suggested transporting floating platforms to the Arctic to replace the sea ice that we’re losing due to human-caused global warming. While the suggestion sounds like it would be helpful in a melting Arctic, giving polar bears a place to rest isn’t practical and doesn't solve their main problem.
Polar bears depend on the sea ice as a platform for hunting seals, the mainstay of their diet. They also rely on the sea ice for breeding, roaming, and sometimes denning. But the most significant thing to understand is that sea ice is far more than a platform: It's an integral part of the Arctic ecosystem. Sea ice is the “soil” for the Arctic marine food web. As the salty ocean water freezes, the salt is pushed out, creating briny channels and pockets underneath the ice. Tiny microorganisms thrive and grow in this unique environment. These small organisms play a key role in the Arctic food chain, creating a food base for Arctic cod, which then feed ice seals, which then feed polar bears.
The sheer scale of newly open water is also a factor. Between 1979 and 2021, the Arctic lost a total 1.35 million square miles of summer sea ice cover—an area four and a half times the size of Texas! Imagine the effort and cost to manufacture and deploy any kind of alternate platform to even come close to the area of sea ice polar bears have already lost.
Rather than being distracted by thoughts of fake ice or floating platforms, societies around the world need to act with urgency to halt global warming. If we don’t, sea ice ultimately will disappear and so will polar bears.
We view the situation of diminishing sea ice in the Arctic as extremely serious but not hopeless. The key to saving sea ice and getting our climate back to functioning the way it should is to move away from using fossil fuels like oil, gas, and coal altogether, shifting instead to energy sources like wind, solar, and water. As this shift is underway, we can also help by embracing energy efficiencies that reduce our use of fossil fuels and by choosing green energy options if they’re available in our communities.
The most recent U.N. climate report underscores the seriousness of the problem but also provides a suite of solutions to address it. We must remember that the answers are there—what we need now is to work together to realize these changes and to urge our leaders to remake our societies in ways that will lead to a more stable, peaceful, and healthy future, acting with the urgency and respect that life across our Earth deserves.
"Polar bears have evolved over hundreds of thousands of years to fit the environment they are in now. They cannot evolve fast enough to live in a world with significantly diminished sea ice."
A 2012 DNA study of polar bears and brown bears suggested the divergence between brown bears and polar bears may have occurred as far back as five million years ago—during the very warm Pliocene Epoch. More recently, genetics researchers have suggested that this split occurred less than 600,000 years ago during the cold Pleistocene. These studies are interesting in terms of understanding how polar bears got to where they are today. But none really alter the risks polar bears face if we allow the climate to continue to warm.
It has been suggested that if polar bears did diverge from a common ancestor with brown bears during the warm Pliocene, perhaps they can survive the global warming humans are now causing. But we must remember that gene trees are not the same as species trees. When the earliest polar bear ancestor diverged from its common ancestor with the brown bear, it was not immediately like today’s polar bear—just as the earliest of humanoids differed greatly from us. Although the polar bear fossil record is sparse, it does show us that by about 120,000 years ago, during the cold Pleistocene, the polar bear was just like it is now. Regardless of its earliest ancestry, the world has been a cold place for about a million years and it was this cool climate that allowed evolution of the ice-loving polar bear of today.
At our current emissions pace, our earth will be warmer in 50 years than it has been for at least a million years. And unlike natural climate cycles of glacial and interglacial periods, the current human-caused warming will only stop if societies work together and halt the rise in atmospheric greenhouse gas concentrations.
Unabated fossil fuel combustion will soon increase Earth’s average temperature beyond anything today’s polar bear, which is highly specialized for hunting in the sea ice environment, has ever experienced. The fossil record shows us that polar bears have been as they are now for over 100,000 years. It also shows us that when sea ice left areas like the Baltic Sea at the end of the Pleistocene, polar bears didn’t adopt a terrestrial lifestyle, they just disappeared from those regions.
We still can halt warming in time to save polar bears over much of their current range. But regardless of how long or how short the polar bear’s evolutionary history has been, saving them is entirely up to us.
“Supplemental feeding at the scale required to maintain polar bear populations would be extremely difficult and expensive, to the point where it is not a practical long-term solution.”
In most jurisdictions around the world, feeding wildlife is prohibited by legislation. There are currently no supplemental feeding efforts for polar bears in any of the five nations where polar bears occur (known as the “Range States”). There are two situations, one in Kaktovik, Alaska, and another occurring in two communities of Chukotka, Russia, that represent artificial feeding. In Kaktovik, polar bears gather to feed on the remains of bowhead whales from subsistence hunts. Although polar bears in the wild will take advantage of dead whales and other marine mammals that are not part of their normal prey, the predictable availability of scraps from whales killed by human hunters is clearly an artificial food supplement. In Russia, managers relocate existing, natural food sources to places on the landscape that may draw polar bears away from coastal communities. Neither of these are formal supplemental feeding programs.
True supplemental feeding (the use of external food sources to help a species survive times when their natural foods are unavailable or in limited supply) has been successfully used, although not without complication, mainly for members of the deer family (e.g. for deer and elk in the U.S.). It also has been used in the management of black and brown bears in the U.S. and brown bears in Europe, specifically as a short-term response during years with a poor natural food supply and as a way to keep bears in the mountains/woods and out of communities, campgrounds, and garbage. Although these cases where bears have been fed certainly do supplement natural foods, they mainly are implemented in the diversionary context—not to enhance survival but to avoid conflicts with humans.
A key aspect of successful supplemental feeding is the short-term or seasonal application and a discrete geographic scale—feeding elk on winter ranges that have been restricted by human developments, for example. In contrast, the nutritional challenge facing polar bears is widespread and increasing. Unless global societies halt the increase in atmospheric concentrations of greenhouse gases, the sea ice habitat polar bears require to catch their seal prey can only decline in temporal and spatial availability, meaning an ever-growing nutritional need. Supplemental feeding at the scale required to mitigate negative population-level impacts of sea ice habitat loss, would be fraught with hurdles including sourcing foods of appropriate nutritional value, possible disease transfer, habituation, and creating artificial gatherings of bears that can increase other threats.
Given the long-term nature of the habitat changes in the Arctic, managers who begin a supplemental feeding program would be committed to maintaining those efforts for a very long time and at very great cost. A decade ago, we estimated that to feed only the bears coming ashore in the Churchill Manitoba area (perhaps the most accessible of all polar bear habitats) would cost over a million dollars per month. Costs of feeding could only grow as more bears in more parts of their range become food stressed. Few jurisdictions are willing to commit to permanent feeding of polar bears at the costs of many millions per month.
The long-term conservation of polar bears as a species can only be achieved by rapid and sustained reductions of global greenhouse gas emissions—combined with the successful management of short-term threats like harvest, disease, toxic pollutants, and denning habitat protection.
Polar Bears International is actively engaged in supporting research that improves our understanding of polar bears and climate impacts while we concurrently add our voice to the growing chorus on the need for climate mitigation and work with management authorities to support conservation efforts on the ground in real time.
"There is no indication that interbreeding between polar bears and grizzlies is caused by climate change. Interbreeding will not help save polar bears because a hybrid is not a polar bear, and if the hybrid were to use sea ice, it would be at the same disadvantage as a polar bear."
Sightings of grizzly/polar bear hybrids in northwestern Canada may or may not be a symptom of global warming. And, even if it is, it has little relevance to future polar bear conservation.
The best available information suggests that polar bears separated from grizzly/brown bears about five million years ago. A recent fossil discovery in Svalbard indicates that polar bear dentition was essentially the same as it is now 120,000 years ago, suggesting that polar bears at that time were essentially the same as those of today.
Research shows that sporadic interbreeding between the two species occurred throughout the polar bear's history. We've known for many decades that polar bears and grizzly/brown bears can interbreed in zoos. It seems reasonable that in areas where their ranges are adjacent—that is, where the sea ice habitats occupied by polar bears and the terrestrial habitats occupied by grizzly/brown bears occur side-by-side—that some interbreeding takes place.
It is important to note that although the summer sea ice has changed greatly in the past few decades, it has changed much less during the polar bear's spring breeding season. And, projections show the extent of sea ice during the spring breeding season will change relatively little well into this century. This means that, at present, by the time the sea ice melts in summer and forces some polar bears onto land — where they might encounter grizzlies — the breeding season for both species is over or at least on the decline.
We must remember that regardless of whether interbreeding increases, it is very unlikely that this poses a threat to polar bears that is in any way on par with the threats of habitat losses and the polar bear's increasing inability to find sufficient food.
Some climate science deniers have speculated that interbreeding will be the salvation of polar bears and therefore we don't have to do anything about global warming to save polar bears. That, of course, is nonsense. In 50 or 60 years (without active and aggressive greenhouse gas mitigation) global temperatures will exceed anything that has occurred at any time during the evolutionary history of polar bears. Polar bears — with or without crossbreeding — simply cannot undo five millions years of evolution in 50 or 60 years.
Crossbreeding or not, with uncontrolled warming, we will see polar bears disappear. We may see grizzly bears expand their range as the climate warms, but that is not the issue we're concerned about. As interesting as it may be from a population genetics standpoint, and as much curiosity as it may generate in the public, the prospect of increases in hybridization between grizzly bears and polar bears is simply not a great conservation issue.
We cannot overemphasize that hybridization provides no solution to the polar bear's dilemma. And to the extent there may be increased hybridization, it probably will be of little consequence to polar bears facing dramatic declines in their habitat base. Polar bears are likely to starve out of their present ranges long before their genes are swamped by those of grizzly bears. If some polar bear genes persist in grizzly bears, after polar bears have disappeared from their current sea ice home, that fact will be irrelevant with regard to efforts to retain the magnificent and highly specialized life form we now know as the polar bear.
Discussions of hybridization aside, it is important to remember that by the time we allow the world to warm enough that the polar bears' sea ice habitat disappears, challenges to humans will be so great that no one will be thinking about polar bear conservation.
"Hunting is important to some Indigenous peoples in terms of both culture and subsistence. Where hunting is allowed, takes are governed by a quota system designed to keep the harvest within the bounds that populations can support.”
The Native people of the north have hunted polar bears for at least 8,000 years. Polar bear hunting plays a central role in long-held traditions and provides food and fiber for traditional lifestyles. Polar bears in some areas were severely over-hunted in the past when trophy hunters utilized light aircraft and large motorized vessels to go into the ice to catch bears in large numbers. Aerial and ship-based trophy hunting was banned by international agreement in 1973.
Over most of the polar bears’ range, polar bears are now mainly hunted by Native peoples. Although the introduction of high-powered rifles and snowmobiles has increased the ability of local Native people to kill polar bears, takes in most areas are governed by quotas and monitoring designed to keep the harvest within the bounds that populations can support. In Canada, home to about two-thirds of the world’s polar bears, each village gets a set number of tags that allow hunters residing there to harvest the number of bears the population can sustain. In some regions, local people can choose to "sell" some tags to sport hunters. That is, they guide a non-resident hunter out on the ice to hunt bears and they allow that non-resident to shoot the bear the guide or another local resident might have shot. Typically, this "sport" hunting results in the take of fewer bears because the sport hunters are normally not as successful as the local hunters.
Historically, this management system had the ability to assure the polar bears' perpetual survival. Like all wildlife, polar bears can be harvested at a certain level without threat to the population welfare. When habitats were stable, a sustainable harvest could be calculated, and the number of hunter tags kept within that sustainable harvest. Unfortunately, polar bear habitat is no longer stable. Polar bears depend on the sea-ice surface to catch their seal prey, and global warming means progressively less sea ice on which they can hunt. Ultimately, all polar bears will see their habitats literally melting under their feet unless we act to curb greenhouse gas emissions. Then, there will be no sustainable harvest anywhere.
At this point, however, global-warming-induced sea ice loss is impacting the hunting success of only some polar bear populations. Those that are not yet seeing the negative effects of habitat loss can provide a limited harvest for some time to come. If societies succeed in halting the increase in atmospheric greenhouse gas concentrations, these harvests could indeed be maintained in the long run and would be truly sustainable. Sustainable harvests in the longer term, therefore, depend on reducing the rise in greenhouse gas concentrations. But for now, some populations may still be safely hunted.
The most important point to remember is that without reductions in greenhouse gas emissions, sea ice can only continue to decline. Without sea ice, there will be no polar bears—and, at that point, we will not be concerned about managing hunts. Research shows, however, that it's not too late to save polar bears and their sea ice home IF we act soon to greatly reduce greenhouse gas emissions.
Answered by Dr. Steven C. Amstrup, chief scientist at Polar Bears International.
“The likelihood of being attacked by a polar bear is very low. There are only one to three instances a year, worldwide.”
It's important to remember that polar bears are very curious. In a world of ice blocks and snow, anything else gets their attention.
Attack circumstances are often related to the way people are camping or to people predisposing themselves to a problem. And with more polar bears driven ashore as the sea ice melts, the chances for encounters increase.
A campsite is an attractive nuisance. It often has bright-colored tents, unusual odors and sounds. A polar bear is an animal that routinely investigates its environment. If you haven’t taken proper measures, you are at risk.
Some attacks happen at night. Bears come in to investigate when there is no movement or sound. They are typically risk averse, so they wait until it’s quiet to let their curiosity take over. The town of Churchill, for example, sits on the polar bear's migration route and is a huge attractant, filled with novel things. A lot of bears have never seen a building and they are somewhat emboldened to investigate.
As a species, we humans are smart enough not to put ourselves at risk, but sometimes we don’t take the proper precautions. We can’t be surprised when bears do what they do. The attacks I’ve researched generally are not from sick bears, or bears on the edge nutritionally, they are the result of bears being bears.
To avoid or survive an attack, first, never go into bear country without a deterrent—a non lethal option like flares or bear spray, a firearm or both. Bear spray, also called pepper spray or capsicum deterrent, is a form of pepper spray used as a tool to minimize injury due to bear-human conflict. It is sprayed at a bear within close range and burns its eyes, nose, and mouth, but causes no lasting damage.
Bear spray is 98 percent effective in all bear cases I studied and has shown promise with polar bears. In two instances of curious polar bears approaching, the bears were deterred by the spray. There's no reason to think that pepper spray would be less effective on polar bears than on other bears. There are only three cases where a person had bear spray and was still mauled (none of these were fatal).
Firearms are 76 percent effective, but people aren’t trained to shoot something that is chasing them down and trying to eat them. Culturally, it is more difficult to get people to carry bear spray instead of a firearm, even though bear spray is more effective and easier to use.
Signal flares are also very effective if the bear is outside of bear spray range (about 20 feet). Signal flares have a 300-foot reach and are waterproof. Bears have a problem with screaming fireballs; that almost always settles it. Handheld flares are also quite effective but of short duration.
Second, if you must go out at night in polar bear country, carry a deterrent, don’t go outside in bear country while under the influence of intoxicating substances, and pay attention to your surroundings. Remember, the risk of getting in trouble is much greater at night.
Third, if camping, string an electric fence or perimeter wire alarm around your camp. An electric fence or tripwire system costs as little as $100 USD, which is a lot less than the value of all the stuff in a camp and certainly of your life.
Why wouldn’t you protect yourself? The odds of a polar bear attack are low, but they aren’t zero.
Answered by Dr. Tom Smith, Professor of Biological Sciences at Brigham Young University and a scientific advisor to Polar Bears International.
"Our goal at PBI is to conserve polar bears and their sea ice habitat, and modern zoos and aquariums can play a critical role in their conservation by acting as research and education centers."
Wild polar bears rely on sea ice for hunting, mating, and raising their young. But Arctic sea ice is retreating due to human-caused global warming, threatening the survival of polar bears. Unless we take action to greatly reduce the carbon emissions responsible for the warming, our research shows that polar bears could all but disappear by the end of the century.
And this is where zoos and aquariums can help.
Few people have the chance to see polar bears in the wild, but millions see them in accredited zoos or aquariums. For example, every year, more people pass through turnstiles in U.S. zoos than all North American sporting events combined! Modern zoos offer a unique opportunity to explain the threats polar bears face and to inspire actions necessary to save them.
This is important because research shows that zoos and aquariums are trusted messengers on climate change and other conservation issues, reaching millions of people every year who might not otherwise hear such messages.
Through our Arctic Ambassador Center network, we work with nearly 50 zoos, aquariums, and wildlife parks in the U.S., Canada, and Europe that share our commitment to polar bear conservation. Our partnership includes training key staff on how to integrate strategically framed content on polar bears and climate change into their keeper talks and outreach—training that takes place through our Climate Alliance program. The coursework relies on tested language from the National Network for Ocean and Climate Change Interpretation (NNOCCI). It helps zoo staff learn to talk about sea ice loss and climate change in ways that promote engagement, resulting in more productive conversations.
Conservation messaging may be the most important contribution zoos and aquariums can make to a secure future for polar bears, but it is not the only contribution.
The role of a modern zoo goes well beyond simply displaying animals and keeping them physically healthy. As many zoos and aquariums with polar bears have come to realize, they have a unique capacity to contribute to conservation-relevant polar bear research projects, providing information that can help us understand and better protect bears in the wild. Our Arctic Ambassador Center partners, for example, have helped researchers working with bears in the wild better understand everything from the polar bear's hearing range, important for setting guidelines for industrial activities that may impact wild bears, to testing a new generation of minimally invasive tracking devices. They’re also helping with studies to assess the reproductive health of wild bears and developing methods to help ensure genetic diversity, among other key projects.
Some have suggested the polar bear’s great movements in the wild, which far exceed the space available in zoo exhibits, leads to polar bears that fare poorly when living in zoos. But modern zoos design exhibits and provide enrichment that keep the bears in their care curious and engaged. They take advantage of the best available veterinary, nutritional, and behavioral science to maximize animal welfare and well-being.
Zoos and aquariums are making an enormous contribution to polar bear conservation—helping to ensure their wild peers will continue to roam the sea ice for generations to come.
"It is likely that some areas that keep more sea ice longer will become 'refugia' for polar bears, but they will not last forever if climate change is not addressed, and they probably will have the capacity to support only a limited number of bears.”
We expect polar bears to disappear from more southerly areas as sea ice there is not persistent for long enough to support them. Some of this disappearance will be due to starvation and some to migration of bears to higher latitudes and cooler conditions. However you should note two things: first, northern areas already have polar bears trying to make a living (so there are not surplus resources in most areas) and second, like other wildlife, polar bears tend to remain in the regions they were born and raised in and try their best to survive. As the world continues to warm, all of the summer sea ice eventually will be gone and polar bears will have few places that can sustain them.
It's a law of physics that the world must warm as greenhouse gas concentrations rise. There will be no new stable state or new equilibrium unless we mitigate the rise of greenhouse gases. Hence, without such mitigation, polar bears will be expected to occur only in increasingly northerly climes until they ultimately wink out. Remember, too, there is only so far they can go. When the last vestiges of sea ice are gone, polar bears will not be far behind.
The only way to stop sea ice decline and assure polar bear persistence is to halt global temperature rise by stabilizing atmospheric greenhouse gas concentrations.
Please visit the Become Part of the Solution section of our website to find out how you can get involved in protecting the polar bears’ future and saving our own. Also check out our Polar Bear Advocacy Toolkit.
"Studies have shown that the calories bears consume on shore do not replace the calories they get from their fat-rich seal diet."
Polar bears in Western Hudson Bay have been forced ashore for increasing lengths of time due to diminished availability of sea ice habitat. When on shore their marine mammal foods are largely unavailable. Longer periods of food deprivation on shore have been linked to declining body stature and survival and to population declines.
Observations of some bears eating eggs of nesting snow geese, and a paper on the topic, have prompted speculation that goose eggs (among other terrestrial sources) could provide an alternate food that might rescue polar bears from global warming. Undoubtedly, some individual polar bears have benefitted and will in the future benefit from consumption of snow-goose eggs and other alternative food sources. But is it probable that such alternate foods are likely to make a difference at the population level?
The paper by Robert Rockwell and others suggests that one seal is energetically equivalent to 88 goose eggs. The average clutch for snow geese is about four eggs, and on average, a polar bear eats a seal about once a week. If a polar bear, stuck on land without access to seals, is going to maintain an energetic position equivalent to the one it had on the sea ice it would need to destroy 22 goose nests each week. If there are about 900 polar bears in the western Hudson Bay populations and they are all on shore searching for goose nests, nearly 20,000 nests would be destroyed each week to support these bears with comparable calories as when on the sea ice.
This of course seems silly in its simplicity. Yet this paper, which some have cited as reason to believe goose eggs might rescue polar bears, concludes that under the most severe predation case, the Cape Churchill snow goose population would decline from nearly 50,000 nesting pairs to fewer than 5,000 in only 25 years. Focused polar bear predation clearly is not sustainable from the goose perspective or that of the polar bear.
Regardless of whether you do a simple calculation or construct complex models, it is clear that the current polar bear population of western Hudson Bay will not be supported by goose eggs. Rockwell and his coauthors, in fact, conclude that predation on snow goose nests may offset some energetic losses polar bears suffer because of reduced time to hunt seals. They do not conclude goose eggs will be the salvation for the polar bear population.
Polar bear biologists have always recognized that some individual bears may benefit from consumption of alternate foods. We have maintained, however, that alternate foods appear unlikely to sustain polar bear populations as we now know them. Studies have shown that polar bears lose about one kilogram of body mass each day they are on land, and that there is no evidence at the population level that they are deriving much sustenance from terrestrial foods. As they come ashore earlier and earlier, polar bears will increasingly search for alternative foods. If, as already shown, all of the existing polar bears were successful in foraging on geese, there soon would be very few geese. Therefore, feeding on geese could be at most a transient salvation, and we have no evidence that other terrestrial foods will be available to supplement the polar bear diet in any meaningful way. More recent studies have further confirmed that most terrestrial sources of nutrition lack the high fat content polar bears are singularly adapted to for survival in a cold climate.
In short, there is little reason to suspect that eating goose eggs or other terrestrial foods will rescue polar bears, and very good reasons to believe that it will not. The only way to preserve polar bears in anything like their current distribution and numbers is to stabilize atmospheric greenhouse gas concentrations so that the necessary sea ice habitats of polar bears are retained.
"Today's projected climate warming is far more intense than anything the species has seen in its evolutionary history."
Fossil evidence makes clear that polar bears were found much further south in Sweden, Denmark and Norway during cooler periods about 10,000 to 12,000 years ago. As the climate warmed, polar bears were extirpated (became locally extinct) from these southern areas.
The last warming period was the Medieval Warm Period (800-1300 A.D.) and the fossil record shows that polar bears were found in Greenland and arctic Canada at this time. Little is known about the ice conditions during this period, but there are indications that it did not change substantially at higher latitudes, meaning that polar bear habitat was largely intact there.
This correlates with the report from the Intergovernmental Panel on Climate Change that states that the warming during the Medieval Warm Period was not necessarily widespread. In fact, there is evidence that in some areas the climate cooled during the Medieval Warm Period. Most important to note is that the period from 1100 to 1200 A.D. was "not warmer than the late 20th century" (Bradley et al., "Climate in Medieval Time," Science October 2003).
The most important consideration for polar bears looking into the future is that today's projected climate warming is far more rapid and intense than anything the species has seen in its evolutionary history. People who are suggesting otherwise are either uninformed or have chosen to ignore the overwhelming scientific evidence on this point. Climate warming results in habitat loss for polar bears and the ecosystem upon which they rely. Habitat loss is a very well documented cause of species range contractions and extinctions across all ecosystems.
Ultimately, the future of polar bears hinges on how warm the climate gets. Scientists have predicted that polar bears will likely persist in the high reaches of the Canadian Arctic and northern Greenland to the end of the century. Of course, this assumes that a smaller population is still genetically and demographically viable and that no serious disease or pollution issues emerge. These latter considerations are often the critical components of a species' demise when forced into a fraction of their former range.
If the carbon build-up and the warming trend continues, however, bears in the high reaches of the Arctic may become extinct as well. Timely action is needed on the part of worldwide leaders to avert this crisis.
Answered by Dr. Andrew Derocher, Professor of Biological Sciences at the University of Alberta and a scientific advisor to Polar Bears International.
"Although it sounds like an easy solution, the risks of relocation far outweigh the benefits.”
This question comes up from time to time. While the concept may seem to have merit intuitively, a closer examination indicates that it is not a simple solution and includes a great deal of risk. In general, translocating or introducing polar bears into Antarctica would be extremely unwise for a number of reasons, some of which follow.
Such an introduction runs counter to the well accepted principles of natural biodiversity management. Sadly, history is replete with examples of species introductions resulting in significant harm to native species and the disruption of entire ecosystems, including: rabbits in Australia, the mongoose to Hawaii, the brown tree snake to Guam, foxes to the Aleutian Islands, and various invasive plant and aquatic species.
The Global Invasive Species Programme (GISP) of the IUCN has the following summary of potential impacts: "Invasive non-native species can harm individual native species or even entire ecosystems, and thus also impact those who depend on natural systems for important resources and products. Unlike other kinds of pollution, these 'biological pollutants' can actually increase in abundance over time and force out native species – by competing with them (for space, water, or food), by eating the native species, spreading new diseases, or so altering the habitat that the native species can no longer survive. In fact, the impacts of non-native species are now recognized as second only to habitat alteration as a factor in the decline and extinction of our American flora and fauna."
• Native wildlife species who reside in or seasonally use Antarctica are generally naïve to surface predators, including resident seals and penguins.
• In general, polar bear predation could result in unanticipated and catastrophic consequences to prey species, particularly naive prey species.
• Penguins would be easy prey for polar bears. Predation of penguins, especially on their breeding grounds, could rapidly devastate their populations.
• Potential disease pathogens could be either introduced from the Arctic by the bears or be present in Antarctica and threaten the bears. Wildlife in both regions are considered to have naïve immune systems as they have been historically isolated from sources/vectors due to their remote locations and the extreme environmental conditions that persist in winter months.
• Although terrestrial and sea ice declines have lagged behind the Arctic, the Antarctic is quickly catching up. From 1979 to 1990, Antarctica was losing ice at a rate of around 40 billion tons per year. However, a recent analysis (Rignot et al., 2019) found that from 2009 to 2018, that ice loss increased to 252 billion tons per year—six times higher than the former rate. In the long run, Antarctic species will be facing similar habitat loss issues as Arctic species.
• Relocation would also violate a number of national and international laws or treaties. Many countries go to great lengths to restrict the import or introduction of exotics into sensitive ecosystems. Because of the relatively simple nature of the Antarctic ecosystem, it’s easy to imagine this being thrown out of balance with the introduction of a new top predator.
While well intentioned, such solutions avoid addressing the primary threat to both the Arctic and Antarctic ecosystems: climate change. We need to all turn our creativity and our passion towards the rapid reduction of burning fossil fuels for energy while transitioning to clean, renewable sources.
“Polar bears and grizzly bears are closely related but, ecologically, they are far apart in how they make a living, and have evolved for different habitats.”
Fostering young cubs has been used on other species, but usually the young are raised in captivity and then placed with wild parents of the same species. Fostering to a different species has been tried but there are often problems with the behavior of the young. How such a method would work on polar bears is difficult to say.
It is likely that a polar bear fostered into a grizzly bear family would behave much like a grizzly bear would. The recent discovery of a polar bear-grizzly bear hybrid in the wild shows that the offspring behaved like the mother (a polar bear) and lived out on the sea ice hunting seals.
It is generally assumed that many behavioral traits in bears are derived from the prolonged period of the mother-offspring bond. However, there could be problems. Polar bears grow to a much larger body size than northern grizzly bears, and it is not clear how a polar bear cub would grow under such a calorie-limited diet. Typical of other species, there may also be difficulties in mate identification: would a polar bear raised by a grizzly look for a polar bear or a grizzly bear to mate with?
Other issues come to mind. The habitat on the mainland for a terrestrial bear is already filled by the grizzly bear. Nature rarely allows two species to fill the same ecological niche. Further, it is unlikely that the High Arctic islands would provide much sustenance for a polar bear trying to live like a grizzly bear.
Further still, polar bears have evolved adaptations for a predatory lifestyle. The claws of a polar bear would be unsuitable for digging out roots or ground squirrels.
There are also problems associated with activities like overwinter denning. All age and sex classes of grizzly bears den overwinter. However, only pregnant female polar bears den in winter to raise young. Terrestrial-living polar bears would do poorly over winter.
Polar bears are formidable predators but grizzly bears are much more opportunist predators. I do not think polar bears raised with grizzlies would find much success in hunting caribou. Caribou are pretty adept at avoiding grizzlies. Changing 400,000 years of evolution—in the span of 100 years—is not a trivial task.
Polar bears and grizzly bears are closely related but, ecologically, they are far apart in how they make a living. At the end of all our interventions, would a polar bear raised as a grizzly bear still be a "polar bear"?
In summary, I hope we never have to resort to such efforts to maintain polar bears in the wild. It seems to me that the solutions are before us and the wise use of resources with incentives to reduce energy consumption are obvious options. Technology can help us achieve climate stabilization—but we need politicians willing to view the world 50 or 100 years ahead and not simply over the span of the short election cycles that are failing our planet.
Answered by Dr. Andrew Derocher, Professor of Biological Sciences at the University of Alberta and a scientific advisor to Polar Bears International.
"Polar bear populations are not booming. Some are rebounding a little after their numbers were vastly reduced by hunting, but that increase is likely to be reversed as the sea ice melts."
One of the most frequent myths we hear about polar bears is that their numbers are increasing and have, in fact, more than doubled over the past thirty years. Tales about how many polar bears there used to be (with claims as low as 5,000 in the 1960s) are undocumented, but cited over and over again.*
One Russian extrapolation presented in 1956 suggested a number of 5,000 to 8,000, but that figure was never accepted by scientists. The fact is that in the 1960s we had no idea how many polar bears there were. Even now, some of our population estimates are only educated guesses, especially in Russia. Back then, the best we had over most of the polar bear's range were uneducated guesses. Polar bear science has come a long way since then.
We do know that some polar bear populations grew after quotas were imposed in Canada, aerial hunting ceased in Alaska, and commercial trapping and hunting was banned across the Arctic. All of these events occurred in the late 60s or early 70s, and we know some populations responded—as you would expect. Some populations were not being hunted back then (or were hunted very little) and those were probably unaffected by these actions.
Across recent history, the sea ice was generally stable, thick and not noticeably in retreat. With stable habitat, polar bears were a renewable resource that could be harvested on a sustainable basis.
However, what happened in the past is increasingly irrelevant. Polar bear habitat is disappearing due to global warming at a rate that has never been seen before. Even the most careful on-the-ground management will ultimately fail if polar bears don't have the required habitat.
Polar bears depend on the sea ice surface to efficiently catch their seal prey. A shorter duration of ice cover over their productive hunting areas means less opportunity to hunt. A reduction in sea ice has been statistically linked to reduced stature and weight in polar bears and to lower survival rates of cubs. So, it doesn't really matter that hunting is now largely under control or that we know a lot about other impacts people might have on bears. Without habitat, polar bears will disappear no matter what else we do.
If a farmer has 100 cows out in a pasture, and every year he goes out and paves over some of his pasture, pretty soon he won't have enough habitat to support 100 cows. And, each time he paves over a little more land, his remaining land will hold fewer cattle. There may be some short-term enhancements of the remaining habitat that will forestall the inevitable. But, when his whole pasture is paved there will be no cows.
Declining habitat now and the assurance it will decline in the future is why polar bears were listed as a threatened species. Discussions about how many bears may have lived in the past before and after hunting quotas have little bearing on the current situation.
Planetary physics requires the world to warm as greenhouse gas concentrations rise, so without greenhouse gas mitigation, the ice will continue to melt. For an animal dependent on sea ice to survive, the prospects are not good. As the ice decline continues, the plight of the polar bear can only worsen.
* For a fascinating look at where this widely repeated myth comes from, read "Magic Number: A sketchy 'fact' about polar bears keeps going … and going .. and going" by Peter Dykstra, published in the Society of Environmental Journalists' SEJournal.
“Satellite collars can give researchers information about the bears that they cannot get any other way. The collars provide a data-rich glimpse into the lives of single polar bears that gives us a representative sample of whole populations.”
Indigenous knowledge is a valuable supplement to the vital information that collars provide but does not entirely replace them. Even Inuit who live among polar bears year round and see the bears regularly do not see the same bear all the time, nor do most travel as far from shore as polar bears do.
As the sea ice declines due to climate change, collared bears show us how their movements and activities may be forced to change with the changing conditions. This gives us important, real-time data on population responses to ongoing sea ice loss from carbon emissions—information that could serve as alarm bells to wildlife managers and policy makers.
What data do researchers collect?
Scientists collect location information, activity rates, and temperature data. Some collars record how much time a bear is spending in the water. The collars tell us such things as what habitat a bear is using at any given time. They also allow us to follow family groups and learn more about cub survival. Collar data is also critical to abundance estimates and population monitoring.
What bears are collared?
Only adult female bears can be safely collared—the necks of adult males are too thick, so a collar would just slip off over their heads. Younger bears are likely to grow rapidly, and current collars cannot accommodate those changes. This means we have less information about the movements of male and subadult bears.
How do researchers put collars on bears?
The bears are first tranquilized with a sedative that makes the experience safe for them and for the researchers. While the bears are tranquilized, researchers obtain various kinds of information, including the animal’s weight, length, and body condition. They also take blood samples that provide even more information, much like an annual doctor’s visit for people. Before departing, researchers carefully fit the collar on the bear. Back at base, researchers are able to confirm successful deployment by checking on collar movements. Some females simply do not like collars and pull them off once awake. In those rare cases, the research team goes back to the capture location and retrieves the collar for use on another bear.
What are collars made of?
Flexible, synthetic material that sheds water and ice and stays flexible in cold temperatures but is strong enough to withstand Arctic marine conditions for at least one year.
How long does the battery in a collar last?
A battery could last long enough that a collar deployed in one spring capture season could still be operating in the capture season of the following year (most polar bear work is done in the late winter and spring when the ice is solid, and the days are long). But collars can also fail and sometimes the bears remove them. So, if they last 12 months, scientists are pretty happy.
How do the collars come off?
Collars are removed in two primary ways: either through direct recapture and removal by the researcher, or via an electronic release mechanism. The basic and most reliable release mechanism has a clock, and researchers can set the day that they want it to drop off. They usually set the timer so that the collar will fall off shortly before the batteries are drained and the collar is no longer transmitting. Once they fall off, a GPS location allows researchers to find the collar (if in a retrievable spot), download any stored data, retrofit, and send it out again.
How many bears are collared each year?
This varies according to project goals, how well-funded a project is in a given year, and how successful researchers are in catching adult females. Collars are expensive to buy and there are additional costs to transmit the data via satellite.
How do collars affect the bears?
Scientists have no evidence that life-threatening injuries or adverse behavior have occurred due to collaring from studies across the Arctic and over several decades. The most comprehensive study of this question found that “…collaring had no effect on polar bear recovery rates, body condition, reproduction or cub survival.”
Polar Bears International appreciates the data that comes from collars, but we also appreciate that this method of data-gathering is intrusive. We understand that tranquilizing and collaring the bears runs counter to Inuit cultural attitudes about how to treat wildlife. For those reasons, we are concurrently supporting the development of less-intrusive monitoring methods.
Both small GPS ear tags and a new effort led by Polar Bears International and 3M to create better adhesive GPS tags look promising. If successful, this would allow researchers to track males and subadults for the first time.
What is Polar Bears International’s position on collaring bears?
Polar Bears International believes that the data provided by collars is not currently obtainable any other way. We believe that this data is critically important to the monitoring and management of the bears. We are supporting the development and use of other technologies, practices, and knowledge sources. We hope that in the future these may enable us to get similar results without using collars.
Rode, K. D., Pagano, A. M., Bromaghin, J. F., Atwood, T. C., Durner, G. M., Simac, K. S., & Amstrup, S. C. (2014). Effects of capturing and collaring on polar bears: Findings from long-term research on the Southern Beaufort Sea population. Wildlife Research, 41(4), 311. doi:10.1071/WR13225
"Residents of many communities in Hudson Bay are seeing more polar bears, real evidence of a change from past conditions. But these increased sightings do not mean the population has grown."
Residents of many communities in Hudson Bay are seeing more polar bears. These polar bears are increasingly getting into food caches, entering camps, and posing risks to communities and residents. The observation that “people are seeing more bears in and around sites of human activities” is real evidence of a change from the past conditions northern residents knew. One interpretation of these observations is that polar bear numbers are high and increasing. The proposed management action in response to that interpretation is to raise harvests. This decision flows from the evidence/knowledge that more bears seen in communities, to concluding there are more bears in the population.
But do these increased sightings mean there are more bears? Western science-based knowledge/evidence shows that in the Southern and Western Hudson Bay populations, polar bear body condition has been declining, polar bears are having fewer cubs, fewer cubs are surviving after birth, and numbers have dropped overall. From that knowledge, the interpretation of western scientists and managers is that these Hudson Bay populations are declining.
It is easy to integrate the two pieces of knowledge/evidence: Lower survival rates and reduced numbers are linked to inadequate nutrition resulting from polar bears being off the ice (and away from their seal prey) for more prolonged periods. Because they are increasingly malnourished while on land for longer periods, more of these bears are venturing into settlement areas looking for food, and more bear/human conflict situations emerge. So, both kinds of knowledge—more bears coming into communities and creating conflict situations, and reduced food availability on ice, making more bears spend time on land where there is little or no food—are consistent with each other. Communities are seeing more bears due to changes in movements and distribution (more time on land) while the overall population continues to decline in abundance.
The difficulty comes not in reconciling the knowledge/evidence, but in reconciling the management actions necessary to deal with the situation.
Polar Bears International is focused on conflict-reduction efforts to prevent dangerous encounters—from taking steps to reduce attractants (using bear-proof garbage cans, for example) to sharing information on the best deterrent tools, such as bear spray.