Wood Bison
History
When the earliest European explorers arrived in western
Canada in the mid-17th century, an estimated 2,000,000 plains bison (Bison
bison bison) ranged over the Canadian prairies. One hundred and
fifty years later, the vast herds that once dominated the open landscapes
had been reduced by excessive slaughter to a few scattered survivors.
In the boreal forest to the north the wood bison (Bison bison athabascae) suffered a similar fate. In the mid-17th
century, it was estimated that 168,000 were scattered unevenly throughout
a vast area in northern Alberta, north-eastern British Columbia, southern
Yukon, the interior of Alaska and the south-western Northwest Territories.
The decline of the wood bison in Canada's North coincided with the rapid
demise of bison on the prairies between 1800 and 1870. By 1875 the wood
bison had disappeared from much of its historic range. In 1891, only 250
remained in the wilderness area between Great Slave Lake and the Sweet
Grass area. The cause of the decline is poorly documented, but records
from trading posts and Northwest Mounted Police files suggest that heavy
hunting following the introduction of firearms into the region was an
important contributing factor. Bison were hunted as a source of meat for
supplying trading posts and for making high quality pemmican to nourish
voyageurs.
Conservation efforts for bison began in Canada in 1877
when the Buffalo Protection Act was passed. However, this legislation was
largely ineffective because of a lack of enforcement.
With the establishment of a Northwest Mounted Police post at Fort
Fitzgerald on the Slave River in 1907, the wood bison began to recover. In 1922,
Wood Buffalo National Park was established to
provide further protection for the wood bison and its habitat.
In 1906, the Canadian Government purchased 709 plains
bison from an American rancher in Montana.
These bison were shipped to Elk Island National Park and were later
transferred to Buffalo Park near Wainwright, Alberta.
The protected bison thrived and in 1925-28, 6,673 plains bison were
transferred from Buffalo Park to the newly established Wood Buffalo
National Park on the Northwest Territories/Alberta border. About 400 of the transplanted bison rapidly migrated to the
lush Sweet Grass area. To
protect those animals, the park was enlarged to its present size of 44,980
km2 .
The transplanted plains bison outnumbered the resident
wood bison by about four to one and the two subspecies readily interbred.
By 1934 the herd had increased to about 12,000 animals.
The Wood Buffalo National Park transplant had two unfortunate
consequences. Firstly, it was thought that the wood bison as a distinct
subspecies had been lost. Secondly, the transplant introduced two cattle
diseases, bovine tuberculosis and brucellosis, into an area where they had been
previously absent.
It was believed that a small population of wood bison
persisted in the remote northern reaches of Wood Buffalo National Park
that had not interbred with the plains bison. In 1959, five specimens were
collected from a herd of about 200 animals in the Needle Lake area and
they were classified as wood bison. Recent
studies have shown that some other subpopulations in the Wood Buffalo Park
area also closely resemble the original wood bison more than the plains
bison.
In 1963, wood bison were captured from the Needle Lake
area of Wood Buffalo National Park to establish a captive breeding herd.
After testing for diseases, 18 bison were transported to an unoccupied
area of historic range a hundred kilometres away on the west side of Great
Slave Lake. These animals
have since given rise to Canada's largest contiguous free-roaming herd of
bison and the largest population of healthy wood bison.
A second round-up of wood bison was held in northern Wood
Buffalo National Park in 1965. Twenty-one animals were successfully
transferred to Elk Island National Park in central Alberta. These
translocated animals carried both bovine tuberculosis and brucellosis, but
through a rigorous management protocol involving isolation and quarantine
of neonates and elimination of original stock, these diseases were
eradicated. This disease-free breeding herd provides founding stock for
captive zoo and park herds, breeding ranches and for reintroducing
free-ranging populations.
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