The polar bear, a large marine mammal and apex predator of the Arctic, navigates one of the planet’s most extreme environments. Its scientific name, Ursus maritimus, or “sea bear,” reflects its profound connection to the frozen seas where it spends much of its life hunting. Understanding their life expectancy reveals their resilience and the challenges they face in a changing world. This article explores the typical lifespan of polar bears and the various elements that influence how long they survive in their natural habitat and in human care.
Typical Lifespan of Polar Bears
In the wild, polar bears typically live between 15 and 18 years, though some individuals reach their early 30s. The oldest recorded wild polar bear lived to be 32. These figures reflect the demanding conditions of the Arctic environment.
In contrast, polar bears under human care often live longer, frequently exceeding 30 years. This extended longevity is attributed to consistent food availability, veterinary attention, and protection from environmental stressors and predators. Debby, a polar bear at Assiniboine Park Zoo, lived to 41. Another captive polar bear lived for 45 years.
Factors Influencing Lifespan
A polar bear’s ability to thrive depends on its primary food source: seals. Successful seal hunting on sea ice is essential for bears to accumulate fat reserves, helping them endure food scarcity, especially during warmer months. If hunting opportunities diminish, bears can face physical exhaustion and reduced lifespans.
Early life is a vulnerable period for polar bears, with high cub mortality rates. On average, only 50 percent of cubs survive their first year, and one-third reach the age of two. Young cubs are susceptible to threats, including starvation if mothers cannot secure enough food, and predation by adult male polar bears.
Polar bears face natural health challenges, including parasites and diseases. They can be exposed to parasitic infections like trichinosis, and bacterial or viral infections such as canine distemper. Dental problems, such as worn or broken teeth, can impair a bear’s ability to hunt and access food, leading to a decline in overall health.
Accidents and intraspecific conflicts contribute to mortality in the wild. As sea ice conditions change, bears may be forced to swim longer distances, increasing the risk of exhaustion and drowning. Confrontations between polar bears, particularly males competing for mates, can result in severe injuries that may lead to premature death if left untreated.
Major Threats to Polar Bear Longevity
The primary threat to polar bear longevity is the rapid loss of Arctic sea ice due to climate change. Sea ice is essential for polar bears to hunt seals, travel, mate, and create maternal dens. As the ice melts earlier and forms later, bears face extended fasting, leading to poorer body condition, reduced reproductive rates, and lower cub survival.
Toxic pollution, specifically persistent organic pollutants (POPs), poses another risk. These chemicals, transported to the Arctic, accumulate in the polar bear’s fatty tissues as they are top predators. High concentrations of POPs can impair immune, digestive, and reproductive systems, and are particularly harmful to cubs who ingest them through contaminated mother’s milk.
Human-polar bear conflicts are increasing as climate change forces bears to spend more time on land, bringing them into closer contact with human settlements. Bears, often driven by hunger, are attracted to human food sources and garbage, which can lead to dangerous encounters. These interactions frequently result in property damage, human injuries, and the killing of bears in self-defense or their relocation from communities.
While regulated hunting of polar bears by Indigenous communities continues, its impact on overall longevity is managed. However, broader issues of habitat degradation, exacerbated by industrial development such as oil and gas exploration, introduce additional risks like habitat destruction and potential oil spills that can directly harm bears.
The warming Arctic environment may introduce novel pathogens and diseases to polar bear populations. As species from more southern ecosystems expand their ranges northward, they can bring new viruses, bacteria, and parasites. Polar bears, already under stress from food scarcity, may have reduced resistance to these emerging health threats, potentially impacting their long-term survival.