On a recent trip out west, I visited Grand Teton and Yellowstone National Parks, where I saw plenty of bison dotting the plains. Or were they buffalo? Is there a difference between the two?

"In North America, the names are used interchangeably for the species Bison bison," Ross MacPhee, Curator of the Department of Mammalogy at the American Museum of Natural History, tells mental_floss in an email. But though both bison and buffalo are bovids, or members of the cattle family, there are some definite differences between them. "Elsewhere—in non-English-speaking Europe, for example—a bison is the European Bison, Bison bonasus, a species very closely related to B. bison," MacPhee says. "A buffalo is either a Cape Buffalo Syncerus (Africa), or Water Buffalo Bubalus (South Asia), neither of which are closely related to either kind of bison." So if you're yearning for a home where the buffalo roam, you'd better move to another continent. 

To tell the difference between a buffalo and a bison, "just look at the horns,” MacPhee says. “[Bison’s] are like typical cow horns; in buffalo, they are relatively huge, sweeping arcs." Bison also have a large shoulder hump. (Telling the difference between the two species of bison is slightly tougher. "An average male European bison has less hair, especially in the cape, or mane," MacPhee says. "Allegedly there is a difference in the angulation of the horns, but I don't see it, or it's too variable to be useful.")

Top: Water Buffalo. Photo by Steve Garvie via Wikimedia Commons. Bottom: Cape Buffalo. Gouldingkin via Wikimedia Commons.

No buffalo have ever lived in North America, according to MacPhee, so how come we call bison by that name? According to the National Park Service, when early explorers came to North America—at which point there may have been as many as 60 million bison on the continent—they thought the animals resembled old world buffalo, and so they called them that. The word comes from the Portuguese bufalo, or "water buffalo," from the Latin word bufalus, a variant of bubalus, which meant "wild ox."

Bison came very close to extinction. In 1883, there were approximately 40 million of the animals in North America; by the 1900s, hunting had reduced the population to under 1000 animals. The bison you see in the National Parks today were bred from just a few individuals from the New York City Zoo and Yellowstone.

Finally, here is a delightful but also very serious flier you receive when you enter Yellowstone National Park. Keep a safe distance from the animals, everybody!