Late winter resource selection and the potential for competition between wood bison and woodland caribou in the Yukon
Year: 2002
Type: dissertation
Abstract: Wood bison (Bison bison athabascae) were reintroduced into southwestern Yukon as part of a national recovery program in the late 1980s.The Yukon Bison Management Plan identified potential impacts of the reintroduced bison on other ecosystem components as a priority management issue.In particular, local residents expressed concern for the indirect effects of bison on the Aishihik woodland caribou (Rangifer tarandus caribou) herd resulting from competition for space and forage during late winter.This project assessed the potential for exploitative competition between bison and caribou by determining resource selection (i.e., use vs. availability) and overlap in resource use across 3 spatial scales: the landscape, habitat, and feeding site.Additionally, bison and caribou diets were analyzed and overlap in forage species use was assessed.Results indicated that bison and caribou used resources in a non-random and selective manner at the levels of the landscape, habitat, and feeding site.The diet of both species suggested preferences for several plant species.Bison and caribou differed significantly in many aspects of resource use and selection at each level of analysis.At the level of the landscape, compared to bison, caribou used higher elevations, and areas that were more rugged and further from water.Similar trends were also evident at the habitat level.Bison selected for graminoid-dominated habitats and caribou selected for coniferous/shrub-dominated habitats.Overlap in resource use at the feeding site level was also minimal since bison selected to forage in areas with high graminoid abundance while caribou foraged in areas with high lichen abundance.The overlap in the diet of bison and caribou was less than 10%; lichens made up nearly 80% of caribou diets while over 80% of bison diets consisted of graminoids.Consequently, under current conditions the potential for exploitative competition between bison and caribou in the late winter is low.Management recommendations were developed based on these findings to address uncertainties in bison and caribou late winter resource selection and overlap and to address local concerns regarding the impacts of bison.Recommendations involved: disseminating results of this study to the local public and other affected parties; periodically monitoring local knowledge and concerns about bison (including interactions between bison and caribou); analyzing fall diets of bison; determining the numerical response of wolves and impacts on caribou if wolves begin to prey on bison; and, monitoring resource use by bison and caribou if they approach the carrying capacity of the Aishihik Lake area.
DOI: 10.11575/prism/23424
Author: Fischer, Lisa A.
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: green
Funder: World Wildlife Fund
OpenAlex ID: W3031844582