Friday seminar: Wolf control, moose control, habitat control: Broad-scale experiments to recover endangered woodland caribou
Friday seminar by Robert Serrouya from Alberta Biodiversity Monitoring Institute, Edmonton, Canada
Adaptive management is frequently promoted as a means of learning how to sustainably manage complex ecosystems. Outcomes, however, are rarely reported, particularly in the context of recovering species at risk. Here, we synthesize adaptive management treatments for recovering woodland caribou, a species that is naturally rare yet covers 3 million km2. The abundant natural resources across their range make woodland caribou recovery one of the greatest conservation challenges in North America. The continental scale of disturbance and time lags of forest succession means that the classic paradigm of a protected area network will likely fail unless population management is also implemented as an emergency measure to avoid extirpation. We report on an experiment covering > 100,000 km2 including 18 populations in western Canada where 12 were subjected to population-based management actions and 6 were reference areas. Treatments were caribou translocations, reductions of overabundant prey and native predators, and creating safe havens for caribou from predators. Eight of 12 treated populations showed increases to population growth rates (λ) after treatments began, ranging from λ = + 0.06 to 0.28. Increases to λ were great enough such that 6 of the 8 populations achieved stable or increasing population growth. Combinations of treatments that affected multiple vital rates produced the highest population growth, yet the level of ecosystem disturbance did not influence population response. The effects of population size on gene flow and drift will also be discussed. By coordinating treatments among scientists, governments, academics and First Nations, socioeconomic inertia was overcome at large spatial scales to credibly inform how to recover this iconic species.