Effects of linear features on resource selection and movement rates of wood bison (Bison bison athabascae)

Abstract

Human-mediated disturbances can lead to novel environmental features that can affect native biota beyond simple habitat loss. In boreal forests of western Canada, linear features (LFs; e.g., pipelines, seismic lines, and roads) are known to alter behaviour, movements, and interactions among species. Understanding LF impacts on native species has therefore been a management priority. Here, we investigate how LFs affect the spatial behaviour of wood bison (Bison bison athabascae Rhoads, 1898), which are designated as “threatened” in Canada. Using data collected from the Ronald Lake population in northeastern Alberta, we assessed how LFs influenced habitat selection and movement of bison by testing support among three hypotheses explaining whether LFs (i) increased forage availability, (ii) enhanced movement efficiency, or (iii) increased predation risk. Results supported the movement efficiency hypothesis as bison were generally ambivalent toward LFs, showing weak selection or avoidance depending on land-cover type, but moved slightly faster when on them. These findings contrast with avoidance behaviours reported for sympatric woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)), which are also “threatened.” Our results should inform critical habitat decisions for wood bison, but we caution that further research is needed to understand the effects of LFs on bison demography.

Assessing the nutritional consequences of switching foraging behavior in wood bison

“…The seasonal switching of foraging behavior correlates with seasonal changes in habitat selection and annual life‐history events of bison. The Ronald Lake bison exhibit strong selection for graminoid‐rich wetlands in the spring and winter, but switch to more use of upland habitats during the summer (DeMars et al, 2020 ). The increased lignification and decreased protein content of graminoids between spring and summer could be a mechanism driving this switch in habitat.…”

“…The range is located in the Hay/Slave River Lowlands of the boreal forest ecoregion (Omernik & Griffith, 2014 ) and is composed of approximately 4% graminoid‐dominated wetlands (e.g., marshes and graminoid fens), 37% upland deciduous, 14% upland pine, 9% upland conifer, 38% peatlands and swamps (e.g., shrubby fens, bogs, swamps), and 4% open water (Figure 1 , Ducks Unlimited Canada, 2016 ). The dominant tree species in upland habitats are quaking aspen ( Populus tremuloides ) in deciduous forests, jack pine ( Pinus banksiana ) in dry sandy sites, and white spruce ( Picea glauca ) in conifer forests (DeMars et al, 2020 ). Other ungulates within the range of the bison include white‐tailed deer ( Odocoileus virginianus ), moose ( Alces americanus ), and occasionally woodland caribou ( Rangifer tarandus ).…”

“… The Ronald Lake wood bison's ( Bison bison athabascae ) home range (100% minimum convex polygon) with a 15‐km buffer, cropped to the west side of the Athabasca River (DeMars et al, 2020 ). The colored (non‐gray) regions represent the home range and each color represents a unique land cover type.…”

“…Additionally, the population is free of bovine tuberculosis and brucellosis that are prevalent in nearby Wood Buffalo National Park (WBNP) populations to the north (Shury et al, 2015). The population's range extends from the southeastern corner of WBNP into Alberta's oil sands region to the south, and bordered to the east by the Athabasca River and to the west by the Birch Mountains (Figure 1, DeMars et al, 2020). The range is located in the Hay/Slave River Lowlands of the boreal forest ecoregion (Omernik & Griffith, 2014) and is composed of approximately 4% graminoid-dominated wetlands (e.g., marshes and graminoid fens), 37% upland deciduous, 14% upland pine, 9% upland conifer, 38% peatlands and swamps (38 Lotek Iridium Track,LOTEK wireless Inc.,Newmarket,Canada; 10 Vectronics GPX Vertex Plus, Vectronics Aerospace GmbH, Berlin, Germany; and 10 Tellus GPS, FollowIT AB, Lindenberg, Sweden) with locations acquired every 90 minutes.…”

“…To avoid overrepresenting an individual location, date, or bison, we only collected one sample per bison location in the field. Then in the lab, we randomly selected three to five fecal samples per season and extracted 5 ml of fecal matter from the center of each sample and combined these to F I G U R E 1 The Ronald Lake wood bison's (Bison bison athabascae) home range (100% minimum convex polygon) with a 15-km buffer, cropped to the west side of the Athabasca River (DeMars et al, 2020). The colored (non-gray) regions represent the home range and each color represents a unique land cover type.…”