Boreal woodland caribou (Rangifer tarandus caribou, hereafter, caribou) is listed as threatened in Canada (COSEWIC 2002). Previous work has demonstrated that caribou achieve their highest densities in low-productivity habitats that support low alternative ungulate and predator densities, providing caribou with refuge from predation. However, variation in the composition, stand age, and connectivity of such habitat across the boreal region, as well as future shifts due to climate change, result in variable caribou population density and population stability. To aid in caribou recovery, we developed habitat models that link caribou population density and demography with habitat at broad spatial scales. We investigated how caribou density varies with landscape features and how population growth rates vary with density and disturbance.
Results/Conclusions
We modeled density as a function of habitats that support alternative ungulates and refuge habitat, and caribou population growth as a function of density and human disturbance (linear features), each summarized for local populations. Preliminary results at the national scale suggest that as the proximity to riparian areas increases, caribou density increases with higher average probability of peat, and that caribou population growth rate decreases with decreasing density (allee effect) and with increasing mean proximity to linear features. We conclude that the habitat required for achieving the highest caribou density varies in different regions of Canada’s boreal forest due to local habitat conditions. Further, caribou population stability is sensitive to local density and does not vary not solely due to the amount of disturbance in a local population range. We discuss future work using caribou behavioural responses to habitat, which will provide predictive links between caribou habitat, density, and population stability as climate changes.