Polar Bear (Ursus maritimus) Fact Sheet: Population & Conservation Status

Global population estimate

• Difficult to assess; polar bears occur at low densities in remote regions (Wiig et al. 2015)
• Approximately 26,000 individuals (range: 22,000–31,000) (Wiig et al. 2015)
  • About half of subpopulations not yet assessed
• Global population decline projected, due to climate-driven sea ice loss (e.g., O’Neill et al. 2008; Regehr et al. 2016)

Subpopulation estimates

• 19 subpopulations recognized by IUCN's Polar Bear Specialist Group (Wiig et al. 2015; Regehr et al. 2016; IUCN/SSC Polar Bear Specialist Group 2021)
  • Largest subpopulations (e.g., Baffin Bay, Chukchi Sea) with available estimates: roughly 2,000–3,000 individuals (Regehr et al. 2018; IUCN/SSC Polar Bear Specialist Group 2021)
  • Smallest subpopulations (e.g., Norwegian Bay, Viscount Melville Sound) with available estimates: roughly 150–200 individuals (IUCN/SSC Polar Bear Specialist Group 2021)
  • East Greenland subpopulation may warrant being split; southern bears have unique reliance on floating ice calved from nearby glaciers (Laidre et al. 2022)
  • See Status Table for other estimates
• Some subpopulations stable, others decreasing or increasing
  • As of 2023, 3 subpopulations (with sufficient data) projected to experience a decline during the next 20 years
  • For trends over the last ~10 years, about half of subpopulations are data deficient (e.g., Dyck et al. 2023)
    • For latest updates to subpopulation estimates, see WWF "Trends in Polar Bear Subpopulation" graphic or IUCN PBSG Status Table
• 6 genetically distinct population clusters identified by Malenfant et al. (2016b)
  • Hudson Bay, Western and Eastern Canadian Arctic Archipelago, Western and Eastern Polar Basin, Norwegian Bay
  • Similar to Paetkau et al. (1999), which identified 4 genetic clusters
  • Some movement of individuals (and genes) among various subpopulations (Wiig et al. 2015)

IUCN Status

• Vulnerable (2015 assessment) (Wiig et al. 2015)
• Potential for large population declines with current trends in sea ice loss (Hunter et al. 2010; Wiig et al. 2015)
  • Certain subpopulations at greater risk due to geography and local seal population densities (Amstrup et al. 2008)

CITES Status

• Appendix II (UNEP 2019)

Climate change

• Sea ice loss can impact (e.g., Hunter et al. 2010; Molnár et al. 2010; Regehr et al. 2010; Rode et al. 2010; Stirling and Derocher 2012; Wiig et al. 2015):
  • Survival of adults and cubs
  • Mating/breeding success
  • Health, body weight, nutrition, and diet
  • Habitat use
  • Physical characteristics (e.g., body size) in some populations
• Polar bears are sea ice and seal specialists (e.g., Stirling and Archibald 1977; Songer et al. 2020; Pagano and Williams 2021)
  • Depend on energy-dense blubber of seals to survive (e.g., Pagano et al. 2018b)
    • Have high calorie needs compared to terrestrial mammals
  • Adapted to walk on ice, not swim long distances
    • Compared to walking, swimming demands a lot of energy to move, keep body temperature up in cold water, and cope with strong waves and currents (e.g., Durner et al. 2011; Pagano et al. 2012; Griffen 2018; Lone et al. 2018a)
    • Also see Locomotion
  • Polar bears more commonly found near open water since 1960s and 1970s
    • Arctic sea ice is breaking up at progressively earlier dates
• Hunger and starvation
  • Longer open water (ice-free period) increases nutritional stress on bears, and affects reproductive success and survival rates (e.g., Stirling et al. 1999; Stirling et al 2008; Molnar et al 2010; Rode et al.2014; Bromaghin et al. 2015; Wiig et al. 2015; Obbard et al. 2016)
  • Some bears unable to meet their energy needs due to a loss of hunting opportunities on sea ice (e.g., Molnár et al. 2010; Regehr et al. 2010; Stirling and Derocher 2012; Obbard et al. 2016; Laidre et al. 2018b; Beyens and van Meurs 2019; Molnár et al. 2020; Florko et al. 2021)
  • Terrestrial foods provide insufficient energy to sustain polar bears (e.g., Ramsay and Hobson 1991; Stirling and Derocher 2012; Rode et al. 2015; Pilfold et al. 2016)
    • Marine prey more energy dense than nearly all terrestrial foods
  • Gain fewer calories in places where their prey's blubber thickness has declined (Stirling 2002; Harwood et al. 2015; Obbard et al. 2016; Atwood et al. 2021; Rode et al. 2018b; Rode et al. 2021b)
  • Lactating mother bears' energy reserves depleted more quickly than non-reproductive individuals (Miller et al. 2022)
    • Cub care may also delay mothers' return to hunting activity
  • Additional factors, such as changes in biological productivity, prey availability, and geographic differences, also likely influence polar bear body condition and survival (Rode et al. 2010; Rode et al. 2014; Bromaghin et al. 2015; Nguyen et al. 2017; Rode et al. 2018b; Songer et al. 2020; Atwood et al. 2021)
• Impact on hunting success and habitat use
  • Declines in sea ice harm polar bears' ability to hunt seals, their primary prey
  • Less sea ice separates habitat areas used by seals (drifting ice) and polar bears (ice attached to land) (e.g., Hamilton et al. 2017)
  • Some bears using larger home ranges or moving longer distances to find food (along ice edges and/or by swimming) (e.g., Auger-Méthé et al. 2016; Pilfold et al. 2017)
    • Search area larger because sea ice is less concentrated (e.g., Greenland; Laidre et al. 2015)
  • On-ice movements and/or habitat use shifting northward in some locations (e.g., Ramsay and Stirling 1990; Pagano et al. 2021; Miller et al. 2022)
  • Amount of time spent on land (vs. pack ice) predicted to continue increasing (Atwood et al. 2016; Rode et al. 2022)
    • May bring some polar bear and human populations into closer contact (Stirling and Derocher 2012; Atwood et al. 2016; Laforge et al. 2017; Wilson et al. 2017)
• Impact on polar bear health and zoonotic pathogens
  • May be exposed to novel pathogens (bacteria, viruses) (Wiig et al. 2015)
    • Encountered when bears:
      • Spend more time on shore
        • Greater immune system activity when on land than when on sea ice (Whiteman et al. 2019)
      • Switch to new prey or food sources (including human garbage)
      • Encounter intermediate disease hosts
      • Are exposed to water carrying infectious cells (oocysts)
  • Higher risk of illness if immune system already taxed by nutritional stress
  • More time spent on land or near human populations may increase bears' exposure to some diseases (e.g., Stirling and Derocher 2012; Pilfold et al. 2021)
    • Humans who consume or handle uncooked or under-cooked bear meat could also be exposed (e.g., to Trichinella)
• Impact on maternal denning behavior
  • Reduced sea ice habitat available for denning (e.g., Stirling and Derocher 2012; Merkel and Aars 2022)
  • Increased maternal denning on land observed in some locations (e.g., Fischbach et al. 2007; Rode et al. 2018a)
    • Detected since the 1980s
  • Declining fall sea ice increases likelihood of den disturbance in some locations (e.g., Patil et al. 2022)
    • Mother bears potentially forced to abandon their dens and/or cubs

Oil and gas extraction

• Oil decomposes slowly and is highly toxic to Polar Bears
  • Ingested through grooming or seal prey exposed to oil
• Concentrated between ice floes during spills
• Commercial activity can disturb denning, hunting, and movement

Pollution

• Chemical
  • Exposed through diet (as top predators) and through contact with polluted water
  • Toxic compounds (heavy metals, organochlorines, chlorinated hydrocarbons, flame retardants) can accumulate in polar bear tissues and organs (Letcher et al. 2010; Dietz et al. 2013a,b); Wiig et al. 2015; Dominique et al. 2020)
    • Many subpopulations exposed to contaminant levels considered harmful to polar bear health and population densities (Nuijten et al. 2016)
    • Chemical load in tissues can be higher for females and cubs
      • Contaminants passed from mother to cub through milk
  • Fat-soluble pollutants may disrupt bear's ability to store and metabolize lipids for energy [Svalbard subpopulation] (Tartu et al. 2017a; Tartu et al. 2017b)
    • Essential to survival in an ecosystem where prey availability and weather change dramatically through the seasons
  • Potentially greater exposure if diet shifts to more subarctic seal species (McKinney et al. 2013)
• Noise
  • Noise from industrial equipment and other human activity may potentially disturb some denning polar bears (e.g., Owen 2009; Larson et al. 2020; Owen et al. 2021)
    • More research needed

Other causes of habitat degradation

• Land development
• Commercial shipping activity
• Recreational activity (e.g., all-terrain vehicles, snowmobiles, aircraft boats)

Also see Polar Bear International's Conservation Concerns information.

Observations from Alaska

• Notable changes in sea ice, such as thinner ice, slushier ice, and later ice return (Rode et al. 2021a)
• Polar bears spending more time on land during the late summer and early fall in recent decades (Pagano et al. 2020; Rode et al. 2021a)
• Bears seasonally arriving on shore being exhausted, after extensive swims from pack ice (Rode et al. 2021a)
• Maternal denning on land (Rode et al. 2021a)

Observations from Greenland

(Laidre et al. 2018a)

• Changes to sea ice and climate
  • Receding glaciers, unstable weather, and warmer temperatures
• Environmental changes have impacted polar bear hunting
  • Some hunting areas shifted closer to human settlements
    • Bears spending time closer to towns
  • More dangerous for hunters to travel on ice via dog sledge
    • Some hunters have switched to using boats
• Changes to polar bear behavior
  • More frequently enter human communities
  • Bears eating more of the seals they kill, including bones
• Diet includes the skin and blubber of seals
  • Also plants, grasses, flowers, berries, and a few cases of seaweed

Hunting

• Illegal hunting
  • Of low concern (Wiig et al. 2015)
• Native subsistence hunting
  • Llegally permitted in the U.S., Canada, and Greenland (at 3–4% of total population) (Wiig et al. 2015)
    • Meat for food
    • Hides for clothing
    • Other parts: small-scale handicrafts
• Sport hunting
  • Only occurs in Canada (Wiig et al. 2015)
    • Must be guided by local Inuit hunters
  • Recent demand for polar bear skins as vanity hangings and floor coverings has declined

Last updated: 2015

Serious concern began in the 1960s after years of increasing hunting.

1965: First international meeting on conservation of Polar Bears in Fairbanks Alaska. Polar Bear Specialist Group established by IUCN

1972: Hunting except for native subsistence purposes prohibited by U.S. Marine Mammal Protection Act

1973: 5 Polar Bear nations, U.S., Canada, Denmark (for Greenland), Soviet Union and Norway (for Spitsbergen) draft agreement to restrict hunting, protect habitat and carry out research on Polar Bears (U.S. ratified in 1976) (Peacock et al. 2011)

1984: Total population in Alaska estimated at 2,000. Hunted by Inuit natives along north coast. 15 villages took 344 animals between 1985-87

1988: Agreement signed by native hunters to jointly manage Polar Bear harvest in Alaska and Canada.

2005: IUCN listed as Vulnerable (A3c) with Decreasing Populations (based on decline in area of occupancy) Version 2009.1

2006: US Fish and Wildlife calls for ban by Canada, Denmark, Norway, Union of Socialist Republics, and United States of "hunting of female Polar Bears with cubs and their cubs" and "hunting of Polar Bears in denning areas during periods when bears are moving into denning areas or are in dens." (Schliebe et al 2006)

2007: Population estimate worldwide, using best available data: 22,000 (USGS 2007)

2007: USGS in September predicts 2/3 of the population will disappear by 2050 and that Polar Bears will be restricted to the Arctic archipelago of Canada / northern Greenland coast

2008: Listed with U.S. Endangered Species Act as Threatened

2009: IUCN Polar Bear Specialist Group documented "unprecedented sea ice retreats in 2007 and 2008" and confirmed earlier conclusion that unchecked global warming will threaten Polar Bears everywhere.

2009: Population estimates for all 19 Polar Bear populations about 20,000 to 25,000 individuals. (IUCN 2009)
Unlike all other bear species, Polar Bears still occupy most of their original habitat.

2009: Polar Bear Specialist Group reveals that eight Polar Bear population groups are estimated to be in decline, up from five in 2005.

2009: U.S. government will set aside 200,541 square miles in Alaska and off its coast as "critical habitat" for polar bears.

2015: Polar Bear Specialist Group concluded one subpopulation had increased, six were stable and, there were insufficient data to provide an assessment of the current trend of the remaining nine. (Wiig et al. 2015)

2016: Revision to the global population estimate (using best available data): 26,000 (Regehr et al. 2016). (Reflected improved data collection in several subpopulations rather than actual changes in global abundance.)

2019: Revision to the global population estimate (using best available data): 23,315 (range: 15,972–31,212). Four subpopulations still lacked any reliable survey of abundance, and most subpopulations lacked enough surveys to estimate trends (Hamilton and Derocher 2019).

2021: PBSG synthesizes all available studies and concluded that over the last 23 years (i.e., two generations of Polar Bears), two subpopulations have “Very Likely Decreased”, one subpopulation has “Likely Decreased”, and other subpopulations continue to lack enough surveys to estimate trends.

How much energy does a polar bear need to survive?

By asking one of the San Diego Zoo's polar bears to walk on a special treadmill, scientists were able to better understand the metabolism of polar bears in the wild.

This research study showed that a polar bear's energy needs are higher than previously thought.

© San Diego Zoo Wildlife Alliance. All rights reserved.

Aars et al (2006)
Amstrup (2003)
Dowsley (2007)
Molnar et al (2010)
Prestrud & Stirling (1994)
Schliebe et al (2006)
Stirling (1993)
Stirling and Derocher (2007)
Stirling et al (2008)
Servheen (1989)
IUCN (2009)