The polar bear is widely recognized as a symbol of the Arctic and is often perceived as the largest land predator on Earth. This perception stems from its imposing presence and its role as a top carnivore in its icy habitat. However, the question of which bear truly holds the title of the largest can lead to a surprising answer for many.
The Polar Bear’s Stature
Polar bears (Ursus maritimus) are massive animals adapted to their Arctic environment. An adult male typically stands 3.5 to 5 feet (1 to 1.5 meters) tall at the shoulder, reaching over 10 feet (3 meters) on its hind legs. Males usually weigh 770 to over 1,300 pounds (350 to 600 kilograms), with some individuals exceeding 2,200 pounds (1,000 kg). Females are considerably smaller, often weighing half as much. These dimensions contribute to the polar bear’s reputation as the largest land carnivore.
The True Giant Among Bears
While polar bears are large, the Kodiak bear (Ursus arctos middendorffi), a subspecies of brown bear, often surpasses them in weight. These bears are exclusively found on the islands of the Kodiak Archipelago in southwest Alaska. Adult male Kodiak bears typically weigh between 600 and 1,400 pounds (272 to 635 kg), with some reaching up to 1,500 pounds (680 kg). They can stand over 10 feet tall on their hind legs and about 5 feet tall on all fours. The largest recorded male Kodiak bear weighed 1,656 pounds (751 kg).
Kodiak bears are omnivores, consuming a varied diet. Their diet includes abundant vegetation like grasses and berries, and a rich supply of salmon during spawning season. Fish are a significant portion, with some males eating around 30 salmon daily during peak season. They also prey on other mammals and scavenge carrion. This diverse, calorie-rich diet and isolated island habitat contribute to their exceptional growth, making them the largest brown bear and often the largest living bear by mass.
Factors Influencing Bear Size
The large size observed in some bear species results from several biological and environmental factors. Diet and the availability of abundant, high-calorie food sources play an important role. For instance, coastal brown bear populations, including Kodiak bears, tend to be larger than their inland counterparts due to access to protein-rich salmon and other marine resources. Bears accumulate fat reserves in late summer and autumn, which are necessary for sustaining them through hibernation.
Habitat and climate also influence bear size. Rich ecosystems provide the resources for bears to grow large. Genetics contribute to large size potential within a species or subspecies, though environmental factors often dictate whether an individual reaches its maximum size. Sex and age are determinants of bear size, with males being larger and growing longer than females. Bears also exhibit seasonal weight variations, being heaviest before hibernation and lightest in spring.