Bison bison

American Bison are highly social animals, forming groups that can range from small family units to massive herds containing thousands of individuals, particularly during migration or when gathering in summer grazing lands. They exhibit a variety of behaviors such as wallowing in dirt to help shed fur and deter flies, and males display aggressive behaviors during the rutting season to compete for mates.

The breeding season, or rut, takes place from July to August. During this time, males compete for access to females through displays of strength and dominance. Females give birth to a single calf after a gestation period of approximately 9 months, usually in April or May. Calves are born with reddish-brown fur and are able to stand and walk within a few hours of birth.

American Bison are characterized by their large, muscular frame, shaggy brown coats, and massive heads with a distinctive hump over their shoulders. Adult males (bulls) are larger than females (cows), with bulls weighing up to 2,000 pounds (900 kg) and cows up to 1,000 pounds (450 kg). Both sexes have short, curved horns that they use for defense and in battles for dominance.

The American Bison once played a central role in the cultures and economies of Native American tribes across the plains. However, by the late 19th century, commercial hunting and policies aimed at displacing Indigenous peoples had nearly driven the species to extinction, with only a few hundred individuals remaining from an estimated 30 to 60 million.

Thanks to conservation efforts initiated in the early 20th century, including the establishment of protected areas and breeding programs, American Bison populations have rebounded, though they no longer roam the plains in the vast herds of their past. The species is currently classified as Near Threatened by the International Union for Conservation of Nature (IUCN), with a total population of approximately 500,000 individuals, most of which are managed as livestock. However, several thousand bison in conservation herds managed by government agencies and Indigenous groups in the United States and Canada are considered wild and genetically pure. Ongoing conservation efforts focus on habitat restoration, maintaining genetic diversity, and reestablishing free-ranging bison herds in suitable areas of their historic range.