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Species at Risk

Wood Bison

Bison bison athabascae

What is the status of the Wood bison?

Close-up of the head of a young Wood Bison calf.
Young calf in Wood Buffalo National Park of Canada, Female usually give birth to a single calf in May after a 270 – 300 days gestation period.
© Parks Canada / (25) / 1990

Wood bison are classified as threatened by the COSEWIC. Historical estimates suggest that there were once over 168,000 wood bison in Canada. Today, the wood bison population in Canada is estimated at around 10,000 animals. This includes free-ranging herds (some of which have been exposed to disease), as well as captive breeding herds. In Wood Buffalo National Park of Canada there are approximately 5000 wood bison today.

Why is the Wood Bison in danger?

Heavy hunting and severe winters are believed to be the main causes for the historical decline of the wood bison population in Canada. The first law prohibiting the hunting of wood bison was introduced in 1877 but later repealed. It wasn’t until 1893, when the wood bison population may have dropped as low as 300 animals, that protective legislation was again enacted. In 1911, buffalo rangers were appointed to strengthen enforcement of the hunting ban. By the time Wood Buffalo National Park of Canada was established in 1922, the wood bison population had increased to approximately 1500 animals.

6673 plains bison from southern Alberta were shipped to the park between 1925 and 1928, bringing tuberculosis and brucellosis with them. These diseases are still found in the Wood Buffalo herd today. Occasional outbreaks of anthrax also occur.

Over the years, there have been instances of mass drownings when herds of bison attempted to cross-thin ice in the spring, and other drownings due to spring floods. 2000 bison drowned in Wood Buffalo National Park of Canada in 1956, and another 3000 animals drowned in 1974. Such events, while rare, are natural and cannot be prevented.