The boreal ecotype of woodland caribou (Rangifer tarandus caribou) is provincially Red-listed in British Columbia and federally listed as Threatened. Population declines of boreal caribou have been attributed to direct and indirect effects of landscape disturbance within and adjacent to caribou range. In western ranges, linear features such as seismic lines, pipelines and roads are a prominent form of disturbance. These features are hypothesized to increase caribou predation rates – the proximate cause of population declines – by facilitating predator movement into caribou range and by increasing predator hunting efficiency. Because of these mechanistic links, limiting predator movement on linear features has become a management priority for stabilizing caribou populations in the long-term.
In this report, we outline a multi-year framework for developing and testing techniques for functionally restoring linear features within caribou range. Functional restoration refers to techniques that aim to limit predator use of linear features to ultimately restore historic caribou-predator encounter rates but that do not necessarily result in the restoration of lined areas to their pre-disturbance structural state (i.e. ecological restoration). Perceived benefits of functional restoration over ecological restoration include more immediate impacts on the targeted biological process, cost-effectiveness and speed of treatment.
The primary objective of our three-year framework is to develop effective techniques that can be deployed in a cost-effective, logistically feasible manner and applied over a biologically meaningful area, which we define as a wolf (Canis lupus) pack’s territory. In the first year, techniques are tested at a small scale to determine their efficacy in excluding predator use of lines. By conducting a literature review and gathering expert opinion at a project scoping meeting, we identified tree felling and fencing as promising techniques to be tested in this phase. In the second year, effective techniques are evaluated on their efficacy in excluding predators from defined areas. Finally, in the third year techniques are deployed over > 50% of a wolf pack’s territory to determine their efficacy in limiting wolf movement rates, kill rates and productivity.
We estimated technique-specific costs and example budgets for each year of the framework. These estimates contain a high degree of uncertainty, primarily related to probable site-specific variation in logistic feasibility, ultimate study design and the adaptive nature of the framework. Nevertheless, cost estimates were below those reported for current ecological restoration initiatives.
Implementation of the framework will require significant financial investment and involvement of all relevant stakeholders, including government, First Nations and industry. Given this and the adaptive nature of the framework, we suggest the formation of an oversight committee as a critical first step toward project initiation.