Polar Bear (Ursus maritimus)
Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.
Genus: Ursus — bears
Species: Ursus maritimus — polar bear, white bear, sea bear
Female: 200 cm (6 ft)
76–127 mm (3–5 in)
Female: typically 150–350 kg (330–770 lb)
White, yellowish, or grayish (varies with season and light). Black nose, lips, and skin.
Distribution & Status
Behavior & Ecology
Circumpolar, Arctic: Canada, United States (Alaska), Greenland/Denmark, Russia, Norway (including Svalbard). A few individuals occasionally reach Iceland.
Most commonly, annual ice fields over shallow coastal waters. Some occur in the permanent multi-year pack ice (Central Arctic). Increased use of land habitats reported in recent decades, due to sea ice loss.
Vulnerable (2015 assessment)
Populations in the Wild
Approximately 26,000 individuals (among 19 subpopulations)
Adapted primarily for walking; conserve energy when moving at slow speeds. Move easily over rugged terrain.
Walk "flat-footed" (plantigrade). Excellent swimmers (use oar-like forepaws) and capable divers (up to 45 ft, though mainly less than 15 ft). Overheat easily when running due to thick fat layer under fur (for insulation against cold).
Depends on season; see Activity Cycle.
Generally solitary, except for females with cubs and brief periods during breeding season. Also when feeding at concentrated food resources (e.g., whale carcasses). Adult males may also congregate along the coast while on land.
Sense of smell well developed. Appear to be sensitive to scent of other polar bears, though role of smell/pheromones not well known.
Highly carnivorous diet — mainly marine mammals, particularly blubber and skin of ringed seals. Population size largely determined by ringed seal availability.
Reproduction & Development
Females: 4–5 years, on average
Typically 2 cubs (about 70% of births).
600–700 g (1 lb 5 oz to 1 lb 9 oz)
Born November to January. Emerge from den in March or April.
Age at Weaning
About 24 to 28 months. Nurse for at least 1 year.
Typical Life Expectancy
Wild populations: 15–18 years
Managed care: median life expectancy of males is about 21 years
© 2009-2023 San Diego Zoo Wildlife Alliance. Science content update and review: 2023.
How to cite: Polar Bear (Ursus maritimus) Fact Sheet. c2009-2023. San Diego (CA): San Diego Zoo Wildlife Alliance; [accessed YYYY Mmm dd]. http://ielc.libguides.com/sdzg/factsheets/ polarbear
(Note: replace YYYY Mmm dd with date accessed, e.g., 2015 Jan 15)
Disclaimer: Although San Diego Zoo Wildlife Alliance makes every attempt to provide accurate information, some of the facts provided may become outdated or replaced by new research findings. Questions and comments may be addressed to email@example.com.
Many thanks to polar bear scientists Drs. Anthony M. Pagano (USGS), Nicholas Pilfold (SDZWA), and John P. Whiteman (Old Dominion University) for providing expert content review of this fact sheet (in September 2023).
View their research publications on Google Scholar: