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Threats
Low genetic diversity owing to 19th-century massive
population reductions
STATUS:
ESA -- ENDANGERED
(as subspecies athabascae)
SIZE:
Weight:
700-2,200 pounds
(320-1,000 kg)
Length:
84-144 inches
(213-366 cm)
HABITAT:
Plains and grasslands, although formerly in
forested areas
CURRENT RANGE:
Yellowstone Park (U.S.), Wood Buffalo Park (Canada) and many other small reserves, both public
and private
CONSERVATION:
CITES trade restrictions
The wood bison, native to the Northwest Territories
of Canada, was heavily interbred with plains bison during early efforts to save the species. This kind
of hybridization is actually
a potential cause of subspecies endangerment. When two subspecies are interbred, each
loses its distinctive identity. It is unclear whether any non-hybridized wood bison survive today.
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From Killing Grounds...
Before 1870, bison and pronghorn were among the most common sights on the North American continent. In the 1820s there were more bison than people in North America -- 60 million by conservative estimates -- but by the mid-1880s they were gone, slaughtered for their hides, for sport, and as part of the military's policy to suppress Indians, for whom buffalo meat and hides were staples. By 1895, about 800 bison survived in the wild in the U.S.
...to Breeding Grounds
For some people, the swift and nearly total destruction of the continent's largest living mammal came as a shock, and gave rise to the first glimmerings of a new understanding: that nature needed to be managed wisely, not pillaged. For the first time the American public became aware that the nation's wildlife was being indiscriminately destroyed. In 1902, a herd of 41 captive and wild bison was placed under government protection in Yellowstone Park; these animals formed the nucleus of the herd that survives today.
At present, the Yellowstone bison herd -- numbering about 2,000 individuals -- is stable and healthy, thanks to continued, strenuous conservation measures. The total North American population is about 30,000 animals. But while the numbers are promising, problems persist. Whenever populations are rebuilt from a core of a very few animals, genetic diversity becomes an issue. Immunity to diseases, for example, is drastically limited by a small gene pool. Today, wild bison are subdivided among dozens of small ranges, so there is limited opportunity to build up genetic diversity within any one group. Only through careful management plans can the bison gene pool be broadened to ensure the long-term survival of the species.
Although once near extinction, the ranch-raised bison
is making a comeback as a meat alternative
to beef -- it is lower in fat, cholesterol,
and calories.
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