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Wood Bison

Wood bison (Bison bison athabascae) are one of two sub-species of the American bison (Bison bison) and are an iconic large herbivore. Compared to their cousin, plains bison (Bison bison bison), wood bison are larger, have long dark brown or black hair forward of their shoulders, and a high hump on their back. Males grow up to six feet tall and weigh up to 2400 pounds, making them the largest native terrestrial mammal in North America. Although females tend to be smaller than males, both sexes grow horns and sexually mature at 2-3 years of age.


A wood bison (Alan & Elaine Wilson; original uploader was Outriggr at en.wikipedia, CC BY-SA 3.0 <>, via Wikimedia Commons).


A plains bison (Lobster1, CC BY-SA 3.0 <>, via Wikimedia Commons).


Where-as plains bison roamed across a vast majority of North America, wood bison were common in Northwestern Canada and Alaska prior to European arrival. Indigenous groups harvested and managed wood bison for millennia before the wood bison population collapsed in the 1800s. The Canadian government enacted legislation to protect wood bison in 1894 when there was only an estimated 150-300 individuals left in the wild.


The federal legislation revoked the rights of hunters, including Indigenous people, to take wood bison with the intent to grow the bison population. The remaining wood bison populations were primarily located in north eastern Alberta and southern Northwest Territories. The modern-day Wood Buffalo National Park (WBNP) was established in 1922 to protect and grow these populations. This was relatively successful as the wood bison population within the park in 1971 was estimated at over 10 000 individuals. In the nearly five decades between the creation of the park and 1971, wood bison were harvested annually by the government. These harvests were initiated in 1929 to supply meat to residential schools and then expanded to supply meat to the Indigenous people in the area. The federal government eventually endeavoured to create a Canadian bison meat market that never caught on with the Canadian public. These harvests were discontinued when WBNP was transferred to the authority of Parks Canada. 


The wood bison in and around WBNP are endemically infected with bovine tuberculosis and bovine brucellosis. Both of these diseases are zoonotic and are able to infect people and livestock. These diseases likely entered the wood bison population when the wood bison interbred with the 6500 plains bison moved into WBNP between 1925 and 1928. Policies to reduce the wolf population in the park likely helped the diseases spread throughout the wood bison population. Infection of the bison with these diseases may have played a role in the decline of the wood bison population beginning in the 1970s. 


Plains bison awaiting transport to WBNP

(Provincial Archives of Alberta, No restrictions, via Wikimedia Commons).

The population continued to decline into the 1990s and wood bison were declared an endangered species in 1978 and are now considered at risk under the Species at Risk Act. The wood bison population did begin increasing at the end of the 20th century. However, the management of brucellosis and bovine tuberculosis is a major limiting factor on the growth of the population. Management over the last few decades has focused on ensuring the diseases do not spread out of WBNP rather than eliminating the diseases within the park.


One of the only specific proposals to deal with the diseases was a 1990 proposal to remove all bison from WBNP and replace them with disease-free animals from other areas, such as Elk Island National Park. This proposal was met with a significant negative reaction from the public and the plan was never implemented. Since then there have been ongoing discussions between rights holders and stakeholders around WBNP. But what members of the communities around the park and the broader population of Alberta and the Northwest Territories think about the bison issue are unknown. We hope to help fill this gap by understanding what people think about the bison health issue and the best way to manage it. 

Plains bison in Ft. McMurray corrals awaiting transport to WBNP (Provincial Archives of Alberta, No restrictions, via Wikimedia Commons).
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