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L.R.P. Williamson et al. 2010. Anthropogenic landscape changes and the conservation of woodland caribou
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2. General Ecology of Woodland Caribou in British Columbia
Similar to the federal system for North American caribou, British Columbia (B.C.) classifies
woodland caribou into three ecotypes: mountain, northern and boreal (Heard and Vagt 1998).
Mountain caribou rely on old-growth subalpine and rugged alpine habitats in the central and
southeastern portions of the province. During winter, these caribou forage on abundant arboreal
lichens (Bryoria spp. and Alectoria sarmentosa) as deep snow restricts there access to terrestrial
lichens or vascular plants (Stevenson and Hatler 1985; Seip and Cichowski 1996; Jones et al. 2007).
Moving to higher elevations to access forage in the winter is an effective strategy for avoiding
predators (Seip and McLellan 2008).
Caribou of the northern ecotype prefer terrestrial lichens (Cladina mitis and Cladonia spp.)
that are found in lower-elevation pine forests or alpine habitats (Heard and Vagt 1998; Johnson et
al. 2004; Jones et al. 2007). Depending on snow conditions and lichen abundance, these caribou
will also forage on arboreal lichens (Bryoria spp.) during the winter months (Johnson et al. 2004).
Northern caribou have highly variable wintering strategies between years, populations and
individuals; some caribou will winter on high, wind-swept alpine ridges, while others prefer
wintering in lower-elevation pine-lichen forests (Bergurud 1978; Terry and Wood 1999; Johnson et
al. 2004; Jones et al. 2007).
The boreal ecotype is found in the northeastern portion of the province and prefers black
spruce (Picea mariana) fen/bog complexes, and tends to avoid well-drained areas (Stuart-Smith et
al. 1997; Dzus 2001). A lack of topographic relief prevents boreal caribou from making
elevational migrations as demonstrated by the mountain and northern ecotypes (Stuart-
Smith et al. 1997; Culling et al. 2006). Ground lichens (Cladina stellaric, C. mitis and C.
rangiferina) become the dominant food source in winter (Schaefer 2008). Boreal caribou now
occupy less than half of their historical range across the continent (Schaefer 2008).
3. Threats to Populations of Woodland Caribou
The abundance and distribution of woodland caribou has been on the decline across North America
since European advancement and colonization (Bergerud 1974; Seip 1992; Vors et al. 2007).
Conservation and management of caribou across Canada is now a high priority due to increasing
rates of decline associated with greater levels of landscape change and anthropogenic disturbance
(Wittmer 2004; Vors and Boyce 2009). Two of the most pressing threats to caribou are habitat loss
and predation; both effects are a direct result of large-scale forestry, energy, and mineral
development (Schaefer 2003; Vors et al. 2007).
Predation is suggested as the leading cause of mortality for woodland caribou in North
America with wolves serving as the primary predator in this multi-carnivore ecosystem (Bergerud
1974; Fuller and Keith 1981; Stewart-Smith et al. 1997; Kinley and Apps 2001; Gustine et al.
2006). Caribou are thought to minimize the risk of predation by using habitats that are spatially
separated from predators (Bergerud et al. 1984; Stuart-Smith et al. 1997; Cumming et al. 1996;
Johnson et al. 2004; Latham 2009). During the calving season, for example, caribou in the
mountainous regions of B.C. and west-central Alberta reduce predation by moving to higher
elevations (Bergurud et al. 1984; Seip 1992; Johnson et al. 2002). Similarly, boreal caribou in
northeastern B.C. use predator refugia such as lakeshores, small islands of mature black spruce,
thick alder stands saturated with water, and old burn sites adjacent to wetlands during the calving
Forest Landscapes and Global Change-New Frontiers in Management, Conservation and Restoration. Proceedings of the IUFRO Landscape Ecology
Working Group International Conference, September 21-27, 2010, Bragança, Portugal. J.C. Azevedo, M. Feliciano, J. Castro & M.A. Pinto (eds.) 2010,
Instituto Politécnico de Bragança, Bragança, Portugal.