Members of the genus
Bison are large
even-toed ungulates within the
subfamily
Bovinae. Two
extant species and four
extinct species are recognized. The surviving
species are the
American bison,
Bison bison (with two subspecies, the
plains bison,
Bison bison bison, and
the
wood bison,
Bison bison
athabascae), found in North America, and the European bison,
or
wisent (
Bison bonasus), found in
Europe and the
Caucasus. While these
species are usually grouped into their own
genus, they are sometimes included in the closely
related genus
Bos, together with
cattle,
gaur,
kouprey and
yaks, with which
bison can
interbreed.
Description
The American bison and the European wisent are the largest
terrestrial
mammals in
North America and
Europe. Bison are nomadic
grazers and travel in
herds,
except for the non-dominant bulls, which travel alone or in small
groups during most of the year.
American bison are known for living in the
Great
Plains
. Both species were hunted close to
extinction during the 19th and 20th centuries but
have since rebounded. The American Plains bison is no longer listed
as endangered, but the Wood Bison is on the
endangered species list in Canada.
Although superficially similar, there are a number of physical and
behavioural differences between the American and European bison.
The American species has 15 ribs, while the European bison has 14.
The American bison has four lumbar vertebrae, while the European
has five. Adult American bison are not as rangy in build, and have
shorter legs. American bison tend to
graze
more, and
browse less than
their European cousins, due to their necks being set differently.
Compared to the American bison, the nose of the European species is
set further 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 through the plane of their faces, making
them more adept at fighting through the interlocking of horns in
the same manner as domestic cattle, unlike the American bison which
favours charging. American bison are more easily tamed than their
European cousins, and breed with domestic cattle more
readily.
Bison are born without their trademark hump and horns and live for
approximately twenty years. They grow to maturity at two to three
years, although males continue to grow until about their seventh
year. Adult bulls express a high degree of dominance
competitiveness during mating season. Male bison fight for females
and these fights often result in injury or death. After the bison
mate, the herd splits up into smaller herds. Calves are born nine
months after mating. The
mothers take care of
and nurse their young for a year.
Male bison grow to as much as long, and tall at the shoulder and
can weigh up to .
Behavior
Wallowing is a common behavior of bison. A bison wallow is a
shallow depression in the soil, either wet or dry. Bison roll in
these depressions, covering themselves with mud or dust. Possible
explanations suggested for wallowing behavior include grooming
behavior associated with moulting, male-male interaction (typically
rutting behavior),
social behavior for group cohesion, play behavior, relief from skin
irritation due to biting insects, reduction of
ectoparasite load (
ticks and
lice), and thermoregulation.In the process of
wallowing bison may become infected by the fatal disease
anthrax, which may occur naturally in the
soil.
Diet
Bison have a fairly simple
diet.
The bison's main
food is
grass. Bison also eat the low lying
shrubbery that is available. In the winter, bison
forage in the
snow looking for grass. If there
is little grass available, bison have to resort to eating the twigs
of shrubs.
Predators
Due to their large size few predators attack bison.
Wolf packs, but not single wolves, could take down a
bison.
Brown bears will also prey on
calves, and have been observed driving off wolves to take over
their kills.
See also
External links
- Gallery of bison tracks & signs, Wikimedia Commons [400]
Gallery
Image:bison herd grazing.JPG|Herd of bison
grazing in Elk Island National Park
, Alberta
,
CanadaImage:Bison feeding - Alberta.jpg|Bison
feeding - Alberta
Image:Bison - Alberta, 1971.jpg|Bison in
winter, AlbertaImage:Bison antiquus p1350717.jpg|
Bison
antiquus skeletonImage:Canis lupus pack surrounding
Bison.jpg|An American Bison standing its ground against a
gray wolf pack.
File:SpringUtah2009 071.JPG|A small group of
bison at Antelope Island State Park
surrounded by the Great Salt Lake
in Utah
.File:Bison Cow and Calf.jpg|Bison cow and
calf
References
- Groves, C. P., 1981. Systematic relationships in the Bovini
(Artiodactyla, Bovidae). Zeitschrift für Zoologische Systematik
und Evolutionsforschung, 4:264-278., quoted
in Don E. Wilson & DeeAnn M. Reeder (editors). 2005. Mammal
Species of the World. A Taxonomic and Geographic Reference
(3rd ed), Johns Hopkins University Press: "Bison". ( online edition)
- The Penny Cyclopædia of the Society for the Diffusion of
Useful Knowledge by Society for the Diffusion of Useful
Knowledge (Great Britain), published by C. Knight, 1835
- Trophy Bowhunting: Plan the Hunt of a Lifetime and Bag One
for the Record Books, by Rick Sapp, Edition: illustrated,
published by Stackpole Books, 2006, ISBN 0811733157,
9780811733151
- American Bison: A Natural History, By Dale F. Lott,
Harry W. Greene, ebrary, Inc, Contributor Harry W. Greene, Edition:
illustrated, Published by University of California Press, 2003 ISBN
0520240626, 9780520240629
- Zoologist: A Monthly Journal of Natural History, By
Edward Newman, James Edmund Harting, Published by J. Van Voorst,
1859