What are the effects of both climate change and land use change on boreal woodland caribou?

Why ask this question?

Caribou are declining across much of their circumpolar range, and both climate and human development have been implicated in these declines. For woodland caribou, an endangered species in Canada and the United States, these same climate and human footprint drivers are likely at play.

Development, in the form of mining, logging, oil sands extraction, and human settlement, creates young conifer forests. These increased ungulate food supplies allow wolf populations to grow, and new linear features such as roads and seismic lines allow wolves to access caribou habitat more effectively. The end result is higher predation rates of wolves on caribou.

But behind this well-known conservation narrative, climate may be playing a larger role than previously thought. Icing events in winter can create an ice layer within or below the snow, preventing caribou from efficiently digging for buried forage. Warmer winters also allowing deer to expand their range northward, while warmer, dryer summers are increasing the the frequency of wildfires, which create young conifer forest that boost deer and moose populations.

How are we answering this question?

To untangle these complex climate and development processes, and figure out whether each process is contributing to caribou declines, we am using long-term climate, land-use, and fire data, combined with 20 years data on caribou reproduction and survival across Western Canada. Here’s what we hope to learn:

  1. How does winter weather interact with industrialization to affect caribou?
  2. What are the likely demographic responses of caribou herds to future changes to climate and land use?
  3. Which management actions are likely to be most effective in conserving caribou for likely climate and land-use scenarios?