The animal that most Americans call a buffalo is actually a bison. There are only 2 buffalo types in the world, and those are the Water Buffalo (found in Asia) and the Cape Buffalo (found in Africa). Early American settlers called bison “bufello” due to the similar appearance between the two animals, and the name “buffalo” stuck for the American variety.

Bison. Photo by Tress Chapin
The American bison sports a large shoulder hump, massive head, and thicker fur. Buffalo have larger horns and less hair.
You may think that Old Faithful is the number one thing that visitors want to see when they come to Yellowstone National Park, but Bison have actually taken over that designation. For many, it is once in a lifetime experience to see such a magnificent animal or get caught in a “bison jam.”
Yellowstone is the only place in the United States where bison (Bison bison) have lived continuously since prehistoric times. Yellowstone bison are exceptional because they comprise the nation’s largest bison population on public land and are among the few bison herds that have not been hybridized through interbreeding with cattle. Unlike most other herds, this population has thousands of individuals that are allowed to roam relatively freely over the expansive landscape of Yellowstone National Park and some nearby areas of Montana. Part of the herd migrates out of Yellowstone to a nearby “nursery” are just north of West Yellowstone in the spring. Once the calves are born, the herd migrates back to the Park.

Winter Bison, Yellowstone National Park
Bison are the largest land-dwelling mammal in North America. Males (2,000 lbs/900 kg) are larger than females (1,100 lbs/500 kg) and both are generally dark chocolate-brown in color, with long hair on their forelegs, head, and shoulders, but short, dense hair (1 in/3 cm) on their flanks and hindquarters. Both sexes have relatively short horns that curve upward, with male’s averaging slightly longer than those of adult females. All bison have a protruding shoulder hump.
Calves of the year are born after 9 to 9½ months of gestation. They are reddish-tan at birth and begin turning brown after 2½ months. Bison may live 12–15 years, and a few live as long as 20 years.
Bison are agile, strong swimmers, and can run 35 miles per hour (55 kph). They can jump over objects about 5 feet (1.5 m) high and have excellent hearing, vision, and sense of smell.
They are social animals that often form herds, which appear to be directed by older females. Group sizes average about 20 bison during winter, but increase in summer to an average of about 200, with a maximum of about 1,000 during the breeding season (known as the rut) in July and August.

Bison Calf by Neal Herbert, YNP
Yellowstone bison feed primarily on grasses and other grass-like plants (more than 90% of their diets) in open grassland and meadow communities throughout the year. They typically forage for 9 to 11 hours daily. Bison are ruminants with a multiple-chambered stomach that includes microorganisms such as bacteria and protozoa to enable them to effectively digest plant material.
Number in Yellowstone – Estimated at 5,500 in August 2016.
WILDLIFE REGULATIONS (Inside and outside of Yellowstone National Park):
- Stay at least 25 yards (23m) from bison and other wildlife and 100 yards (91m) from bears and wolves.
- Do not feed or approach wildlife. You are not safe just because there is a small creek or hill between you – they move quicker than you think and are unpredictable.
- All animals in the Yellowstone Ecosystem are wild and should be given respect – this is their home – you are only visiting.
Sources: Yellowstone National Park (nps.gov/yell), livescience.com, diffen.com
For other wildlife and bird watching ideas click here.