Bison or Buffalo?Bison and buffalo belong to the Bovidae, or cattle, family, but they are different species and have distinct characteristics. Many people refer to the creatures that once roamed the American West as buffalo; however, these animals are actually American bison, and they are only found in North America. On the other hand, two species of buffalo—the cape buffalo and the water buffalo—are found in Africa and Asia, respectively. Unlike the American bison, which has short horns similar to those of cows, buffalo have broad, sweeping horns. In addition, the American bison has a broad head carried low and a massive hump at the shoulders. In contrast, buffalo don't have shoulder humps and their heads are smaller than the bison's.What is the main, or central, idea of the passage?