Wood Bison
Description
The
wood bison is the largest native terrestrial mammal in North America. They
are generally taller and less stocky than plains bison. At maturity wood
bison bulls measure over 1.8 m at the shoulder and weigh over 1000 kg.
Cows are smaller, averaging 550 kg. The wood bison is larger than the
plains bison, has a more pronounced hump and has less hair on the front
legs and throat. Bison have a woolly undercoat overlain by longer guard
hairs, which makes them resistant to cold temperatures.
The beard tends to be less developed in wood bison than in plains
bison. Male and female bison have short black horns extending upwards from the
sides of the head.
The
sex of a bison can be determined from the shape and size of its horns. The male's
horns have a thicker base than the female's. In females the horns tend to be slender and commonly show a slight
backwards recurve near the ends.
Classifying Bison
Using Horn Shape and Size
Calves
Young
of the year of both sexes.
Calves are typically born in April-May, with calving largely
completed by early July. At birth, calves have reddish-tan coats
which turn dark chocolate brown by about 3 months of age.
Yearlings
Animals
of both sexes with spike-shaped horns (10-30 cm length).
Cows
Horns
are thinner than those of any male.
Horns are curved toward the middle line of the skull or
towards the back forming an S-shape in older cows. Front of the
skull is narrower than that of adult bulls.
Juvenile
Bulls
Base
of horns is wider than cows.
Horns point upward or outwards, but are never curved to point
towards each other.
Sub-adult
Bulls
Hair
on head and shoulders is shorter than in adult bulls. Horns point
straight up or towards the middle line of the skull.
Base of horns is wider than in cows.
Adult Bulls
Body
size is much larger than cows. Hair on chest and head is fully
developed, leaving no open space between the horns.
Horns are curved towards the middle line of the skull.
Older bulls can be identified by their worn horn tips. |
