The influence of wolves on the ecology of mountain caribou

• Main Author: Allison, Bradley Armstrong
• Format: Others
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/8102

The wolf (Canis lupus)/mountain caribou (Rangifer tarandus caribou) spatial separation model (Seip 1992a) was examined in highland and mountainous areas of east central and southeastern British Columbia to determine the influence of wolves on mountain caribou ecology. Three key elements investigated were: the importance of wolf predation as a mountain caribou mortality factor, the elevational relationships of mountain caribou, wolves, and moose (Alces alces), and the seasonal dietary importance of moose to wolves. Mountain caribou mortality data from the Columbia Mountains and Quesnel Lake supported the hypothesis that wolf predation is greater in highland than in mountainous areas. Wolf predation was the main mortality factor of caribou in the highlands around Quesnel Lake, but was a minor factor in the other three study areas. Wolf predation at Quesnel Lake occurred primarily during summer/fall at low elevations. Mountain caribou, wolf and moose radio-telemetry data suggested that wolves in both highland and mountainous areas are more closely associated elevationally with moose than caribou throughout the year. Caribou in highland areas appeared as adept as those in rugged mountains at spacing elevationally away from wolves during all seasons. Significant elevational overlap between wolves and caribou occurred only in the rugged Columbia Mountains, and then, only during summer/fall. Wolf scats from the Columbia Mountains indicated that mountain caribou were of lesser dietary importance than moose to wolves throughout the year. Moose, particularly in winter, were the main diet item of wolves. Beaver was an important dietary item of wolves during summer/fall. Elevational separation appears inadequate in explaining the variation in wolf predation on mountain caribou in the highland and mountainous study areas. Differences in wolf densities and the relative densities of moose and caribou may be the main factors influencing the susceptibility of mountain caribou to wolf predation. It is recommended that studies be conducted in both topography types across a wide range of caribou and moose densities to better explain the influence of wolves on mountain caribou ecology. In addition, it will be necessary to compare the geographic distribution of mountain caribou and wolves to assess if geographic rather than elevational separation occurs. Determining how timber harvesting impacts the numerical and spatial responses of wolves, mountain caribou and moose is also recommended. === Land and Food Systems, Faculty of === Graduate