Alaska is home to roughly 100,000 black bears and an estimated 30,000 brown bears (including grizzlies), making it by far the most bear-dense state in the United States. A much smaller number of polar bears, likely in the low thousands, occupy the northern and northwestern coasts. Those headline figures, drawn from decades of Alaska Department of Fish and Game surveys, are useful starting points, but the reality beneath them is far messier. Bear populations in Alaska shift dramatically from one region to the next, driven by salmon runs, sea ice, island geography, and contentious management policies that make accurate counting an ongoing challenge.
Brown Bears Across the State
Brown bears and grizzly bears are the same species, Ursus arctos. In Alaska, “brown bear” typically refers to the larger coastal animals that fatten on salmon, while “grizzly” describes the leaner interior populations. The statewide estimate of about 30,000 has held roughly steady for years, but that number is really a patchwork of regional surveys stitched together over time. Individual study areas illustrate how the math works. On the Kenai Peninsula, for example, researchers estimated about 582 brown bears peninsula-wide, extrapolating from a study-area density of 42 bears per 1,000 square kilometers of available habitat.1The Journal of Wildlife Management. Estimation of the brown bear population on the Kenai Peninsula, Alaska Multiply that kind of regional work across dozens of game management units, each with its own terrain, food supply, and survey history, and you get the statewide total. It is not a census so much as a best estimate assembled over many years.
What makes the number deceptive is how unevenly bears are distributed. Coastal brown bears with access to abundant salmon runs can be found at densities 6 to 80 times higher than interior bears that rely on berries, roots, and the occasional moose calf.2Wildlife Monographs. Brown and black bear density estimation in Alaska using radiotelemetry and replicated mark-resight techniques A place like Katmai National Park, where salmon crowd into shallow streams by the millions, can support a remarkable concentration of bears in a relatively small area. Drive a few hundred miles inland and you might cover a vast stretch of boreal forest before encountering a single grizzly track.
Why Salmon Runs Shape Bear Numbers
The connection between salmon and brown bear density is not just a loose correlation. Modeling work has shown that brown bear populations are closely tied to the amount of salmon they can access, and that salmon management decisions aimed at commercial fisheries inadvertently affect bears. When salmon escapement (the number of fish allowed past harvest to spawn) roughly doubled from a regional lower goal to an upper goal in one studied system, mean salmon consumption by bears increased by about 20%. But when escapement dropped below minimum goals, consumption declined rapidly.3Ecosphere. Modeling the interaction between salmon management and consumption by coastal brown bears In other words, how many fish managers let through directly influences how many bears the landscape can support.
How individual bears use that salmon also matters. Research tracking brown bears at a major salmon stream found that the total mass of salmon a bear consumed depended more on how long it spent foraging than on how many fish were in the river. During a year with 140% more salmon, bears ate 51% more fish, but the variation among individuals was best explained by how many days each bear showed up to feed.4Scientific Reports. Phenological tracking associated with increased salmon consumption by brown bears Experienced, dominant bears that arrive early and stay late pack on the most weight before winter. Younger or subordinate animals that get pushed off the best fishing spots may get far less, which over time can influence whether they survive and reproduce. The population-level implication is that raw fish abundance sets a ceiling, but individual behavior and social hierarchy determine how close the bear population actually gets to that ceiling.
Black Bears, Alaska’s Most Abundant Ursid
Black bears outnumber brown bears in Alaska by roughly three to one, with the statewide population estimated at about 100,000. They occupy most of the state except the far north, the western coast, and some islands in the Alexander Archipelago. Despite being the most common bear species in Alaska, black bears get far less public attention than brown bears or polar bears, partly because they tend to avoid the dramatic salmon congregations that make coastal grizzlies photogenic and partly because they are smaller, more secretive, and less likely to cause headline-making encounters.
Their resilience is striking. A study in western Interior Alaska tracked what happened after black bears were almost entirely removed from a 1,368-square-kilometer study area through translocation. The pre-removal population of roughly 83 to 109 independent bears was reduced by 96%, to somewhere between 0 and 13 bears, by late spring 2004. Yet within just three years the population had bounced back to 56 to 84 individuals, and by 2010 it had fully recovered to pre-removal levels or higher. Both males and females recolonized the area quickly, suggesting a surrounding population large enough to serve as a steady source of immigrants.5Wildlife Society Bulletin. Black bear population reduction and recovery in western Interior Alaska That four-to-six-year recovery timeline is remarkably fast for a large omnivore and speaks to the quality of Interior Alaska’s habitat and the size of the broader black bear population feeding into depleted areas.
Polar Bears Along the Northern Coast
Alaska’s polar bears belong primarily to two recognized subpopulations. The Southern Beaufort Sea subpopulation ranges along the northern coast from about Utqiagvik (formerly Barrow) eastward into Canada. The Chukchi Sea subpopulation occupies the northwestern coast and extends into Russian waters. Estimating their numbers is especially difficult because polar bears spend much of their lives on sea ice, far from shore, and the two subpopulations cross international boundaries.
The Southern Beaufort Sea subpopulation is the better-studied group on the Alaska side. Long-term research found that these bears experienced a period of low survival from 2003 to 2006, which drove a substantial decline in abundance. Survival improved modestly from 2006 to 2008 and then rebounded to relatively high levels for most of the remaining study period. Abundance tracked survival, declining sharply from 2003 to 2006 and then fluctuating around an average of about 565 bears through 2015. Even with that partial recovery, the population over that decade was smaller than at any point since the U.S. Marine Mammal Protection Act was passed in 1972.6PubMed Central. Survival and abundance of polar bears in Alaska’s Beaufort Sea, 2001-2016
The Chukchi Sea subpopulation is harder to pin down, but recent circumpolar assessments have generally put it in the range of roughly 2,000 to 3,000 bears, shared between Alaska and Russia. Together, Alaska likely supports somewhere between 3,000 and 4,000 polar bears across both subpopulations, though uncertainty in the Chukchi numbers keeps the total fuzzy.
How Sea Ice Decline Is Changing Polar Bear Habitat
Retreating Arctic sea ice is not just a symbolic concern for polar bears. It is reshaping the geography of their daily lives. Bears that stayed on the summer sea ice between 1999 and 2016 used home ranges that were, on average, 64% larger than those of bears tracked from 1986 to 1998. The center of those summer ranges also shifted about 193 kilometers farther north-northeast as the ice edge retreated. In practical terms, bears that once spent summer hunting seals on relatively compact ice fields were suddenly traveling across vast stretches of open water and degraded ice to find productive hunting grounds.7Ecosphere. Effects of sea ice decline and summer land use on polar bear home range size in the Beaufort Sea
Not all bears followed the ice north. Some have shifted to spending summers on land instead, and those bears had annual home ranges 88% smaller than their ice-dwelling counterparts during the same period.7Ecosphere. Effects of sea ice decline and summer land use on polar bear home range size in the Beaufort Sea Land-based bears may scavenge whale carcasses, eat vegetation, or simply rest and wait for the ice to return. Whether land use is a viable long-term strategy or just a temporary refuge as ice habitat disappears is one of the central questions in polar bear conservation. What is clear is that the environment polar bears evolved to exploit is shrinking, and both their movement patterns and their numbers reflect that reality.
Grizzlies Expanding to New Islands
While polar bears lose habitat in the north, brown bears appear to be gaining it elsewhere. Research combining scientific surveys with traditional and local ecological knowledge from Indigenous communities found that grizzly bears are now present on at least 10 islands in the Alexander Archipelago of Southeast Alaska that fall outside their current management boundary. Local knowledge suggested this expansion had accelerated over the preceding decade, and scientific methods including remote cameras and genetic sampling confirmed occupation on every island where local observers reported bears.8PubMed Central. Indigenous knowledge and science unite to reveal spatial and temporal dimensions of distributional shift in wildlife of conservation concern
A similar pattern is playing out farther north. Observations from the Canadian subarctic have documented grizzly bears pushing into areas historically occupied only by polar bears and black bears, with evidence suggesting they are denning locally rather than just passing through.9Arctic Science. Novel range overlap of three ursids in the Canadian subarctic These range shifts matter for population estimates because they mean the geographic boundaries used to count and manage bears are becoming outdated. A grizzly that swims to an island previously considered “black bear only” territory is not captured in the management unit’s brown bear estimate. And where grizzlies move in, they may compete with or displace black bears, reshuffling local numbers in ways that region-by-region surveys can take years to detect.
Ancient Genetic Divisions Hidden in the Population
Alaska’s bear populations carry genetic signatures that stretch back hundreds of thousands, and in some cases millions, of years. The brown bears on Admiralty, Baranof, and Chichagof Islands (known collectively as the ABC Islands) in Southeast Alaska have long intrigued geneticists. Recent genomic work revealed that these bears belong to a distinct genetic cluster that also includes a small mainland pocket west of the Coast Mountains. The analysis traced the origin of this cluster to the Late Glacial period, roughly 11,700 to 19,000 years ago, when bears recolonized Southeast Alaska after the last ice age. The Chatham Strait has kept the Admiralty Island bears separated from the Baranof and Chichagof populations throughout the Holocene, preserving their genetic distinctiveness even though the islands are not far apart.10PubMed Central. Population-genomics reveals a dual ancestry of grizzly bears
Black bears in Southeast Alaska tell an even older story. Two lineages, estimated to have diverged roughly 1.8 million years ago based on mitochondrial DNA, remain genetically distinct in the region despite having lived in proximity since recolonization began around 18,000 years ago. Nuclear genetic markers confirmed that contemporary movement between the lineages has not been enough to erase their differences. The geography that keeps them apart includes narrow saltwater straits, expansive ice fields, slender beach fringes, and inland bays that function as barriers to gene flow.11Journal of Zoology. Black bears in Southeast Alaska: The fate of two ancient lineages in the face of contemporary movement
These genetic divisions are more than academic curiosities. They mean that a “brown bear” on Admiralty Island and a “brown bear” on the Alaska Peninsula are separated by thousands of years of independent evolution. Managing them as a single statewide population, with a single harvest quota framework, glosses over real biological differences that could matter for long-term survival. And for black bears, losing one of those ancient lineages through habitat destruction or overharvest would erase a branch of evolutionary history that predates the genus Homo.
The Management Controversy
Alaska manages its bears under a legal and political framework that is unusual by global standards. In most of the state, brown bears, black bears, and gray wolves are managed in ways intended to significantly reduce their abundance, with the explicit goal of increasing the number of moose and caribou available for human hunters. A critique published in PLOS Biology described this as “a reversion to outdated management concepts” and noted that Alaska may be unique in the world in having this predator-suppression priority both widespread and mandated by state law.12PubMed Central. Large carnivores under assault in Alaska
The same critique pointed out that this management occurs without effective monitoring programs designed to scientifically evaluate the impacts on predator populations.12PubMed Central. Large carnivores under assault in Alaska That is a significant gap. If the goal is to keep bear numbers lower in some areas to boost ungulate populations, you need reliable bear counts to know whether you are succeeding, overcorrecting, or having no effect at all. In practice, many of Alaska’s game management units rely on population estimates that are a decade or more old, supplemented by harvest data and occasional aerial surveys. The statewide totals of 30,000 brown bears and 100,000 black bears are useful benchmarks, but they may lag behind actual population trends in specific regions, especially where management is actively suppressing numbers.
Federal land managers sometimes take a different approach, and disagreements between state and federal authorities over bear management on national parks and wildlife refuges have produced public battles. The tension is fundamentally about what bears are for: a harvestable resource managed for maximum ungulate yield, or a component of intact ecosystems managed for ecological balance. Both philosophies produce different target population sizes, and the bear population someone considers “healthy” depends on which framework they are using.
Parasites and Disease in a Remote Landscape
One factor that could influence bear numbers but is rarely discussed is disease. A parasitological survey of Alaska brown bears examined fecal samples and blood from animals across the state’s relatively undisturbed habitats. The results were reassuring: helminth eggs showed up at low rates, including hookworm in 10% of samples and roundworm in about 3%. Screening for blood parasites like Babesia and the bacterium Bartonella came back negative in every animal tested. Antibodies to the mite that causes sarcoptic mange were detected in about 10% of bears sampled, but no clinical mange was observed.13PubMed. Survey for Selected Parasites in Alaska Brown Bears (Ursus arctos)
Researchers noted that these low parasite levels are consistent with what you would expect from bear populations living in large, relatively intact habitats near the northern edge of their range. Cold winters, low bear densities in interior regions, and limited overlap with domestic livestock all likely keep pathogen transmission rates down. Whether that changes as the climate warms and bears shift their ranges into new areas, potentially picking up novel parasites or encountering higher densities of other wildlife, is an open question. For now, disease does not appear to be a significant driver of bear population dynamics in Alaska, which is a notable contrast to some lower-latitude bear populations where mange, canine distemper, and other pathogens can cause real mortality.
Why Counting Bears Remains So Difficult
People sometimes assume that wildlife agencies know exactly how many bears are out there, the way a national census counts people. The reality is that bear population estimates are expensive, labor-intensive, and often outdated by the time they are published. Common methods include mark-recapture studies where bears are captured, tagged, and later re-counted; aerial surveys that work better in open tundra than in dense forest; DNA-based methods that collect hair samples from rub trees and bait stations and use genetic identification to estimate how many individuals left samples; and statistical modeling that extrapolates from small study areas to larger regions.
Each method has blind spots. Aerial surveys undercount bears in thick cover. Mark-recapture studies require recapturing enough animals to produce reliable estimates, and bears that are trap-shy or live in remote areas may never enter the sample. DNA methods are powerful but expensive to deploy at scale. And extrapolation always rests on assumptions about whether the study area is representative of the broader region, which it often is not. The Kenai Peninsula brown bear estimate, for instance, assumed that bear density in unsurveyed portions of the peninsula matched density in the study area. If bears cluster around certain drainages and avoid others, that assumption could be off.
For polar bears, the challenge is compounded by the fact that the animals spend months on shifting sea ice that crosses international boundaries. A bear counted in Alaska’s Beaufort Sea in March might be in Canadian waters by June. Coordinating surveys between countries, standardizing methods, and accounting for bears that are simply never detected makes polar bear estimates among the most uncertain of any large mammal on Earth. The 565-bear average for the Southern Beaufort Sea subpopulation came with a credible interval stretching from 340 to 920, a nearly threefold range that reflects genuine scientific uncertainty rather than sloppy counting.6PubMed Central. Survival and abundance of polar bears in Alaska’s Beaufort Sea, 2001-2016
All of this means that Alaska’s headline bear numbers are best understood as rough order-of-magnitude guides. The state has a lot of brown bears, even more black bears, and a comparatively small and potentially vulnerable population of polar bears. The exact figures carry real uncertainty, and in some regions the most recent estimates are old enough that the actual population may have shifted in either direction. For anyone trying to assess whether Alaska’s bears are thriving, stable, or declining, the honest answer is that it depends on the species, the region, and how recently anyone bothered to look.