The question of which bear is the largest often sparks debate, as different metrics can lead to varying conclusions. While many bear species are large, the polar bear and the Kodiak bear consistently emerge as the top contenders. Understanding their sizes requires delving into specific measurements and the factors that influence them.
The Two Largest Bears: Polar and Kodiak
The polar bear (Ursus maritimus) and the Kodiak bear (Ursus arctos middendorffi) are widely recognized as the largest bear species in the world. Their impressive sizes are supported by their unique habitats and diets.
Polar bears, primarily found in the Arctic, are the largest extant species of bear by body mass and are considered the largest land carnivores. Adult male polar bears typically weigh between 300 to 800 kg (660 to 1,760 lb) and can measure 200 to 250 cm (6.6 to 8.2 ft) in length. They can stand 130 to 160 cm (4.3 to 5.2 ft) tall at the shoulder, and up to 10 feet (3.05 m) on their hind legs. The largest recorded polar bear weighed 1,002 kg (2,209 lb) and stood approximately 3.7 meters (12 ft) long. Their diet is highly carnivorous, specializing in seals, particularly ringed and bearded seals, which provide energy-rich blubber essential for survival in their cold environment.
Kodiak bears, a subspecies of brown bear found exclusively on the Kodiak Archipelago in southwest Alaska, rival polar bears in size. Adult male Kodiak bears typically weigh between 272 to 635 kg (600 to 1,400 lb), with mature males averaging 477 to 534 kg (1,052 to 1,177 lb) throughout the year, and potentially reaching up to 680 kg (1,500 lb) at peak times. They stand approximately 1.22 to 1.52 meters (4 to 5 ft) tall at the shoulder when on all fours and can exceed 3 meters (10 ft) when standing on their hind legs. The largest recorded wild male Kodiak bear weighed 751 kg (1,656 lb). Their omnivorous diet includes a significant amount of vegetation like sedges, forbs, and berries, but salmon is a crucial protein source, especially during seasonal runs.
Understanding Bear Size Metrics
Determining the “largest” bear is not always straightforward due to various measurement metrics. Body weight is a common metric, but it fluctuates significantly throughout the year based on food availability and preparation for hibernation.
Other measurements include length from nose to tail, shoulder height when on all fours, and standing height on hind legs. Each of these metrics can present a different perspective on overall size. For example, a bear might be heavier but shorter at the shoulder than another. Skull size, specifically total skull length plus width, is also used in some record-keeping.
Individual bear size is influenced by factors such as age, sex, and food availability. Males are consistently larger than females across bear species. Bears typically weigh the least when emerging from their dens in spring and can increase their weight by 20–30% during late summer and autumn in preparation for hibernation. Geographic location and specific dietary habits, such as access to protein-rich food sources like salmon, also play a significant role in a bear’s potential for growth.
Other Notable Large Bear Species
While polar bears and Kodiak bears are the primary contenders for the largest, several other bear species are also notably large. Brown bears (Ursus arctos), which include various subspecies beyond the Kodiak bear, exhibit a wide range of sizes. Mainland grizzly bears (Ursus arctos horribilis), for instance, are a well-known North American brown bear subspecies. Average males weigh between 135 to 390 kg (297 to 859 lb) and stand up to 2.44 meters (8 ft) tall on their hind legs, but they are typically smaller than Kodiak bears.
American black bears (Ursus americanus) are the most common and widely distributed bear species in North America. Adult males typically weigh between 59 to 299 kg (130 to 660 lb) and measure 1.2 to 2.1 meters (4 to 7 ft) from nose to tail. They stand 0.61 to 0.91 meters (2 to 3 ft) tall at the shoulder.
Asiatic black bears (Ursus thibetanus), also known as moon bears, are medium-sized bears found across Asia. They are generally more slender than brown bears, with males weighing 60 to 200 kg (130 to 440 lb) and standing 70 to 100 cm (28 to 39 in) at the shoulder.
Sun bears (Helarctos malayanus), native to Southeast Asia, are the smallest of all bear species. Adults weigh 25 to 65 kg (55 to 143 lb) and stand nearly 70 cm (28 in) at the shoulder.