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 is
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.
Shoulder heights in the species can range from 152 to 186 cm
(60 to 73 in). Mature bulls tend to be considerably
larger than cows. The heaviest wild bull ever recorded
weighed 1,270 kg (2,800 lb).
When raised in captivity and farmed for meat, the bison can
grow unnaturally heavy and the largest semi domestic bison
weighed 1,724 kg (3,801 lb).
The heads and forequarters are massive, and both sexes have
short, curved horns that can grow up to 2 ft (61 cm) long,
which they use in fighting for status within the herd and for
Bison are herbivores, grazing
on the grasses and sedges of the North American prairies.
Their daily schedule involves two-hour periods of grazing,
resting, and cud chewing, then moving to a new location to
graze again. Bison bulls of that age may try to mate with
cows, but if more mature bulls are present, they may not be
able to compete until they reach five years of age.
For the first two months of
life, calves are lighter in color than mature bison. One very
rare condition is the white buffalo, in which the calf turns
Differences from European bison
Although they are superficially
similar, the American and European bison exhibit a number of
physical and behavioral differences. Adult American bison are
slightly heavier on average because of their less rangy build,
and have shorter legs, which render them slightly shorter at
the shoulder. American bison tend to graze more, and browse
less than their European relatives, because their necks are
set differently. Compared to the nose of the American bison,
that of the European species is set farther forward than the
forehead when the neck is in a neutral position. The body of
the American bison is hairier, though its tail has less hair
than that of the European bison. The horns of the European
bison point forward through the plane of its face, making it
more adept at fighting through the interlocking of horns in
the same manner as domestic cattle, unlike the American bison
which favors charging.
American bison are more easily tamed than the European, and
breed more readily with domestic cattle.