A bison is not a cow. While the two animals share a general appearance and are biologically related, they are distinctly separate species. The term “cow” refers specifically to a female domesticated cattle, whereas bison are wild North American and European bovines that have never been fully domesticated.
The Definitive Taxonomic Difference
The primary distinction between a bison and a cow lies in their scientific classification at the genus level. Both are members of the same biological family, Bovidae, which is a group that includes cloven-hoofed, ruminant mammals like antelopes, goats, and sheep. This shared family explains their similar overall body plan and digestive system.
Domestic cattle, including European and Zebu types, belong to the genus Bos (Bos taurus or Bos indicus). The American bison, conversely, belongs to the distinct genus Bison (Bison bison). This separation at the genus level confirms they are separate biological entities whose evolutionary paths diverged millions of years ago.
Observable Physical Distinctions
One of the most immediate visual differences is the bison’s massive shoulder hump, which is absent in most domestic cattle breeds. This hump is a crest of muscle and bone that supports the bison’s huge head. Due to this muscular structure, the bison exhibits a front-heavy body proportion with a sharply sloped back, while cattle have a more uniformly proportioned, straight back.
The head and coat also offer clear distinctions for identification. Bison possess a much larger, blockier head relative to their body size, often covered in a dense, shaggy coat that extends down the neck and forms a noticeable beard. Domestic cattle typically have a smaller, narrower head and a shorter, smoother coat across their entire body.
Bison horns are short, sharp, and black, set low on the sides of the skull, curving upward. Cattle horns, when present, are often longer and vary widely in shape depending on the specific breed.
Genetic Proximity: The Case of Beefalo
Despite their separation into different genera, bison and domestic cattle possess genetic compatibility that allows for successful interbreeding. The resulting hybrid offspring is known as Beefalo, or historically, Cattalo. This ability to crossbreed shows that while they are distinct species, they are closely related within the Bovidae family.
Modern Beefalo is a specific breed standardized to possess three-eighths (37.5%) bison genetics and five-eighths (62.5%) domestic cattle genetics. Hybridization was pursued to combine the superior meat quality and hardiness of the bison with the docility and high fertility of cattle.