Species Spotlight: Woodland Caribou

Populations of boreal Woodland Caribou are declining throughout much of their distribution, including in the six ranges that completely or partially overlap with the Al-Pac FMA (Figure: Woodland Caribou Range Map). This species is federally^[1] and provincially^[2] listed as Threatened because of these declines. Landscape disturbance and climate change are implicated in Woodland Caribou declines because:

• Landscape disturbance—both natural (e.g., fire) and human-caused (e.g., forest harvesting)—results in the creation of younger forests, which increases the number of prey species other than Woodland Caribou, mainly Moose and Deer^[3,4,5].
• Human footprint features, such as roads, pipelines, and seismic lines allow wolves to move "faster and farther", increasing their hunting efficiency^[6]. These linear features serve as access routes for wolves into previously inaccessible Woodland Caribou habitat^[7]. 
• Climate change has resulted in milder winters, which favour the northward expansion of White-tailed Deer^[8] into caribou ranges.

Ultimately, these factors, alone or in combination, result in larger populations of Moose and Deer in Woodland Caribou range; higher prey densities support increased numbers of predators, which leads to higher caribou predation. While the links between caribou population decline and these factors are well-established, the relative importance of each factor on caribou populations is largely unknown. This knowledge is critical for developing effective and cost-efficient strategies for conserving caribou.

Therefore, Al-Pac, as part of its involvement in the Regional Industry Caribou Collaboration (RICC), is working with the ABMI’s Caribou Monitoring Unit (CMU) on four projects assessing the relative importance of natural disturbance, human footprint, and climate change in terms of their impact on caribou populations. These projects are described below; more details on the CMU are available in Collaborators and Contributors.

Purpose: Assess the degree to which human footprint may be influencing predator and prey population densities by potentially improving regional habitat quality for black bears and white-tailed deer species.

Background: Human land-use increases the availability of young forest, potentially increasing the available food for moose, deer, and black bears, which consequently increases the density of caribou predators (e.g. wolves and bears).

Preliminary Findings: Cumulative human footprint under current conditions improves regional habitat quality for black bears and white-tailed deer by ~6%. Seismic lines alone accounted for 1% and 2% improvement in habitat quality for bears and deer, respectively.

Management Implications: These preliminary results suggest that human footprint likely does not substantially influence deer and bear habitat quality, though human footprint may operate by alternative mechanisms to increase predation risk to caribou.