Habitat and Movement Ecology of Grizzly Bears in the Mackenzie Delta, NWT

IN THE 1960S AND 1970S, the Mackenzie Delta region of the Northwest Territories in Canada’s Western Arctic was on the brink of an oil and gas “boom”; however, pipeline construction was delayed following Thomas Berger’s recommendation for a 10-year moratorium so that Native land claims could be settled. Today, the Mackenzie Delta is the proposed site for the new Mackenzie Gas Project, which will include an increase in the number of exploration and production wells and the construction of a pipeline and gathering system with associated facilities, as well as airfields and winter and all-weather roads, and result in landscape-level changes (Imperial Oil Resources Ventures Limited, 2004; Cizek and Montgomery, 2005). Wildlife managers and the affected communities are concerned that sensitive species like the barren-ground grizzly bear (Ursus arctos) could be adversely affected by increasing oil and gas development. Historically, grizzly bear declines in North America have resulted from the fragmentation of habitats by human settlements, roads, agriculture, human intolerance, and inadequate planning in the early stages that precede development (Servheen et al., 1999). Wildlife managers lack the current information on the ecology of this Arctic population of grizzlies needed for effective mitigation of the effects of disturbance caused by hydrocarbon development. Low density, high mobility, and large home ranges describe Arctic grizzly bear populations (Ferguson and McLoughlin, 2000). When compared to other large carnivores, grizzlies are considered to have a lower ecological resilience, which is characterized by low population density, low fecundity, and low dispersal ability through developed areas (Weaver et al., 1996). Low resilience suggests that grizzlies are especially vulnerable to development-related disturbance. The sensitivity of the species makes it difficult for population numbers to increase in multi-use landscapes where the cumulative impacts of industry, subsistence and sport hunting, problem and defence kills, and recreational activities are the norm. The Mackenzie Gas Project will transect areas occupied by grizzly bears within the Inuvialuit Settlement Region, which is also at the northernmost edge of their geographical range. At these northern latitudes, grizzly bears must accumulate enough energy reserves to last the 6–7 months of winter dormancy (Nagy et al., 1983). We do not know what effects a pipeline will have on the grizzlies of the Mackenzie Delta, but it could make it more difficult for them to meet their resource needs given a short active 5–6 month period (Nagy et al., 1983). Harding and Nagy (1980) predicted that hydrocarbon development in the region could be detrimental to grizzly bears because of the loss of available resources, and that mortality from problem bear-human interaction could result in population decline. The primary goals of my project are to collect baseline information on grizzly bear ecology before pipeline construction begins, to describe annual and seasonal home range size and distribution, and to identify important habitats. The information gained will form the foundation for model development to assess the affect of oil and gas–related activities on grizzly bears. Major project objectives are 1) to describe habitat selection patterns, 2) to quantify movement patterns, and 3) to incorporate these patterns into a scenario-based modelling approach to assess the response of grizzly bears to pipeline-related development.