Bison are grazers and feed primarily on grasses, sedges and forbs.

Wood bison are the largest land animal in the entire Western Hemisphere! A large, mature bull wood bison will often weigh 2,250 pounds versus the 1,900 pounds of the smaller plains bison. A mature cow wood bison will weigh in at about 1,000 pounds.  

Bison typically breed in July and August, with dominant bulls fathering most of the calves in each herd. Gestation lasts 9 months, with most bison calves born in May, but can be born from April to August. Cows can have their first calf at 3 years old and will generally have one calf, twice every three years. Calves are reddish in color and will darken to brown at around 15 weeks. Calves weigh in at 40 pounds when newborn and run within hours of birth, begin grazing in their first week of life and are weaned in the fall. They begin to grow horns and develop a “hump” at about two months.

In, 2015, the Alaska Department of Fish and Game released a total of 130 wood bison along the Innoko River near the community of Shageluk. The Alaska Wildlife Conservation Center partnered with ADF&G and assisted with the holding, quarantine and breeding facility for the wood bison to be released. To learn more about the reintroduction, check out our Wood Bison Reintroduction page for more details.

Two subspecies of bison live in Alaska; the plains bison and the wood bison. Plains bison were introduced to Delta Junction in 1928 from the National Bison Range in Montana. There are approximately 1,000 wild plains bison in four separate herds in Alaska – Delta Junction, Copper River, Chitina River, and Farewell. Small domestic herds of plains bison in agricultural areas on the mainland and on Kodiak and Popov Islands. Unlike many plains bison existing in the contiguous United States today, the bison from the Farewell herd near McGrath has no evidence of exposure to cattle genetics. This means that Alaska’s plains bison could one day serve as a “genetic reservoir” for future plains bison conservation efforts.

Although plains bison are similar in appearance to wood bison, wood bison are on average about 15% heavier than plains bison. A wood bison’s hump is taller and has its highest point forward of the front legs. The wood bison has woolly hair along its ribs, whereas plains bison have very short hair. Wood bison vocalizations are different vocalizations from those of plains bison, and the wood bison’s social interactions during the rut tend to be less violent than plains bison. Some of these differences are evidence of the wood bison’s adaptation to its northern environment: pockets of grassy meadow habitat within the sea of boreal forest, where temperatures can be quite cold, and snow can be deep for extended periods.

In North America, a common term for bison is “buffalo.” This derives from the French word “boeuf,” meaning “ox.” While the usage of “buffalo” to describe bison remains popular due to cultural traditions and aesthetics, the word is also reserved for the Cape buffalo (Syncerus caffer) of Africa and the water buffalo (Bubalus arnee) of Asia.