Burly, shaggy bison (Bison bison), the North American hoofed mammals that, for many people, embody the American West, are often referred to as buffalo.
But even though they are in the same family group as Old World buffalo species — the Asian water buffalo (Bubalus bubalis) and the African cape buffalo (Syncerus caffer) — bison are not closely related to those species, making the common name "buffalo" misleading.
When the first European settlers arrived in North America, as many as 60 million bison inhabited the continent's grasslands, according to the U.S. Fish and Wildlife Service (USFWS). These early settlers likely saw similarities between bison, the continent's largest land animal, and known buffalo species, the National Park Service (NPS) explained on its website. The settlers referred to the large beasts as "bison" and "buffalo" interchangeably, and the name "buffalo," though scientifically inaccurate, stuck.
The mistake is somewhat understandable. Both bison and buffalo belong to the Bovidae family, which consists of more than 100 species of hoofed mammals called ungulates, including buffalo, bison, antelopes, gazelles, cattle, sheep and goats. The American bison species is found only in North America, and its closest relative, the European bison (Bison bonasus), can be found in Belarus, Lithuania, Poland, Romania, Russian Federation, Slovakia, Ukraine and Kyrgyzstan, where about 1,800 free-ranging individual bison are currently estimated to roam, according to the International Union for Conservation of Nature.
Bison likely first arrived in North America around 400,000 years ago, traveling across an ancient land bridge from Asia, according to the Department of the Interior (DOI).
But even though bison and buffalo are similarly large, cattle-like animals, there are striking physical differences that distinguish them.
The American bison — which can weigh up to 2,000 lbs. (900 kilograms) — sports an unusually massive head and a considerable shoulder hump, both of which are covered with thick, woolly fur. The enormous, heavy muscles in the hump allow bison to use their heads as powerful snowplows in the winter, pushing aside masses of snow by swinging their heads from side to side, the NPS reported.
Bison's heads can also be used as battering rams, to drive off predators or to compete for females, according to the NPS.
By comparison, the buffalo of Africa and Asia have no hump whatsoever, and their skulls are smaller than those of bison. But while they may come up short on head size, both buffalo species more than make up for that in the breadth of their impressive horns.
Asian buffalo have large, crescent-shaped horns that curve upward and can span over 6 feet (2 meters) in length, according to the Encyclopedia of Life (EOL). Wild males can weigh over 2,600 lbs. (1,200 kg), though domesticated Asian buffalo, which are widespread across Asia, typically weigh about half as much as that — around 1,200 lbs. (550 kg), EOL explained.
African cape buffalo are native to the savannas and grasslands of southern, western, eastern and central Africa, and the animals usually congregate near water, according to the African Wildlife Foundation (AWF). Males are equipped with a head shield from which the horns sprout, sweeping downward before curling back up again, and can weigh as much as 1,500 lbs. (680 kg), the AWF reported.
Currently, about 10,000 wild bison still roam 12 states in North America, where the animals forage for an average of 9 to 12 hours each day for weeds, grasses and leafy plants, according to the DOI.
Originally published on Live Science.
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Mindy Weisberger is a Live Science editor for the channels Animals and Planet Earth. She also reports on general science, covering climate change, paleontology, biology, and space. Mindy studied film at Columbia University; prior to Live Science she produced, wrote and directed media for the American Museum of Natural History in New York City. Her videos about dinosaurs, astrophysics, biodiversity and evolution appear in museums and science centers worldwide, earning awards such as the CINE Golden Eagle and the Communicator Award of Excellence. Her writing has also appeared in Scientific American, The Washington Post and How It Works Magazine.