The American bison also known as the American buffalo is the largest animal in North America and once roamed the prairies in massive herds. A bison has a shaggy, long, dark brown winter coat, and a lighter weight, lighter brown summer coat. As is typical in ungulates, the male bison are slightly larger than the female and, in some cases, can be considerably heavier. Plains bison are often in the smaller range of sizes, and Wood bison in the larger range. Head and body length ranges from 6.6 to 11.5 ft long, the tail adding 12 to 36 in. Shoulder height in the species can range from 60 to 73 in. Weight can range from 701 to 2,205 lb. The heaviest wild bull ever recorded weighed 2,800 lb. Bison are also known as the Thunderbeast because if they’re thousands of bison on a stamped, they sound like thunder over the prairies and they can run faster than most horses. American bisons live in river valleys, and on prairies and plains. Typical habitat is open or semi-open grasslands, as well as sagebrush, semi-arid lands and scrublands. Some lightly wooded areas are also known historically to have supported bison. Bison will also graze in hilly or mountainous areas where the slopes are not steep. Though not particularly known as high altitude animals, bison in the Yellowstone Park bison herd are frequently found at elevations above 8,000 feet. Bison are migratory and herd migrations can be directional as well as altitudinal in some areas. Bison have usual daily movements between foraging sites during the summer. In a montane valley, bison have been recorded traveling, on average, 3.2 km a day. The summer ranges of bison appear to be influenced by seasonal vegetation changes, interspersion and size of foraging sites, the rut and the number of biting insects. The size of preserve and availability of water may also be a factor. Bison are largely grazers, eating primarily grasses and sedges. On shortgrass pasture, bison predominantly consume warm season grasses. On mixed prairie, it appears that cool season grasses, including some sedges, compose 79–96% of their diet. In montane and northern areas, sedges are selected throughout the year. Bison also drink water or consume snow on a daily basis. Bison mate in late spring and summer in more open plain areas. During fall and winter, bison tend to gather in more wooded areas. During this time, bison partake in horning behaviors. They will rub their horns against trees, young saplings and even utility poles. Aromatic trees like cedars and pine seem to be preferred. Horning appears to be associated with insect defense as it occurs most often in the fall when the insect population is at its highest. Cedar and pines emit an aroma after bison horn them and this seems to be used as a deterrent for insects. Female bison live in maternal herds which include other females and their offspring. Male offspring leave their maternal herd when around three years old and will either live alone or join other males in bachelor herds. Male and female herds usually do not mingle until the breeding season, which can occur from July through September. Buffalo hunting was an activity fundamental to the Midwestern Native Americans, which was later adopted by American professional hunters, leading to the near extinction of the species around the year 1890. It has since begun to recover.