American Bison - Buffalo Field Campaign

Figure 2.1 Original ranges of plains bison and wood bison. Recreated by Boyd (2003) based on van Zyll de Jong (1986) and Stephenson et al. (2001).
Modern bison originally ranged across most of North America
(Figure 2.1). Plains bison were most abundant on the Great
Plains, but also radiated eastward into the Great Lakes region,
over the Allegheny Mountains toward the eastern seaboard,
northward as far as northern New England, and then south into
Florida; westward, they were found in Nevada and parts of the
Great Basin, the Cascade and Rocky Mountains northward to
mid-Alberta and Saskatchewan prairie lands, and further south
along the Gulf of Mexico into Mexico (Danz 1997; Reynolds et
al. 1982). There are records of bison occurring at surprisingly
high elevations in mountainous regions, particularly along
the Front Range of the Rocky Mountains (Fryxell 1928; Kay
and White 2001; Meagher 1986). Evidence also indicates that
bison inhabited areas of the Greater Southwest, including
Arizona, New Mexico, and northern Mexico, areas not generally
recognised as within the original range of plains bison (Truett
1996). Whether apparent or real, bison scarcity in the American
Southwest is usually attributed to a combination of insufficient
water and grass and human hunting (Truett 1996). The original
range of wood bison includes northern Alberta, north-eastern
British Columbia, a small area of north-western Saskatchewan,
the western Northwest Territories, Yukon, and much of Alaska
(Stephenson et al. 2001). More recent research incorporating
oral narratives of aboriginal people in Alaska, Yukon, and
Northwest Territories, in combination with archaeological and
palaeontological records, demonstrates that wood bison were
present in the Yukon and Alaska within the last two centuries,
and that these areas are within the original range of the
subspecies (Lotenberg 1996; Stephenson et al. 2001).
2.3 Abundance
Historical and archaeological records demonstrate that plains
bison thrived on the grasslands of the Great Plains (Malainey
and Sherriff 1996; Shaw and Lee 1997). Explorers, settlers,
and Euroamerican hunters described enormous herds of
plains bison, with population estimates ranging from 15 to 100
million (Dary 1989; Shaw 1995). In the 1890s, naturalist Ernest
Thompson Seton posited the widely accepted estimate for
American bison at 60 million (Dary 1989; McHugh 1972; Roe
1970; Shaw 1995).
Several quantitative and qualitative methods have been used
to estimate pre-settlement bison abundance, including direct
observation, carrying capacity calculations, and counts of
bison killed for market in the late 1800s. Even when used in
combination, all methods are fraught with uncertainty, untested,
American Bison: Status Survey and Conservation Guidelines 2010 7