Bison are hoofed MAMMALS of the cattle family (Bovidae),
classified by mammalogists in to 2 species, European bison
(Bison bonasus) also known as wisent, and the American bison
(Bison bison). Although the latter species has been split into 2
subspecies, the prairie bison and the wood bison, but a critical
reexamination of the evidence provides no taxonomic evidence
that these subspecies are valid.  The North American species,
better known as buffalo, has short, black, curved horns; a
beard, shoulder hump, short tail; and long, shaggy, woolly hair
on the shoulders, 4 legs, head and throat. Bulls attain adult
size at 6-8 years; cows, at approximately 4 years. Bison can
live in excess of 20 years.  The northern bison are larger in
body than the southern bison, but so are other ungulate species
such as MOOSE, WAPITI and DEER. Body size in ungulates and
WOLVES increases with latitude up to 65° N, but reverses
thereafter. The coat patterns as described for the wood bison
appear to be an artifact of captivity in ELK