Two new papers on wildlife forecasts for caribou in Northwest Territories, Canada

In a great collaboration with Dr Frances Stewart and Dr Tati Micheletti (lead authors; but there were many others involved!), we have recently published new forecasts of caribou habitat availability and demographics for the Northwest Territories (NWT), Canada, (Stewart and Micheletti et al. 2023) and an assessment of the role of caribou as an umbrella species for conservation of boreal landbirds (Micheletti et al. 2023).

Boreal caribou habitat and demography over the next century in the NWT

In Stewart and Micheletti et al. (2023), we combined a complex landscape model (LandR; Barros et al. 2023), with integrated vegetation and fire dynamics (and their responses to climate change), with boreal caribou resource selection models and demographic models to forecast changes in boreal caribou habitat availability and reproductive rates over the next century, in the NWT.

Overall, our models projected important shifts in boreal caribou habitat and relatively stable or declining growth rates. But results differed between locations (for instance, we saw habitat gains in the north and declines in the south). Importantly, we quantified uncertainty around our projections and noticed it is particularly high with respect to population growth rates.

Mean (right) and standard deviation (left) of boreal caribou habitat changes projected by a resource selection function model. From Stewart and Micheletti et al. 2023.

Population growth rate (lambda) changes over the next century, for different populations (colours) and climate change scenarios (lines). From Stewart and Micheletti et al. 2023.

These results were summarised in the infographic below, and have received media coverage on Cabin Radio and the What On Earth show from CBC.

Created by Jeff Dixon

The role of boreal caribou as an umbrella species for boreal landbird conservation in the NWT

In Micheletti et al. (2023) we used a similar modelling framework to project habitat for boreal caribou and several boreal landbird species, and to assess whether by protecting boreal caribou habitat we can also protect landbird habitat. We combined the same dynamic landscape models and caribou habitat model as in Stewart and Micheletti et al. (2023), with landbird habitat suitability models, and projected caribou and bird habitat changes for the next century, under different climate scenarios. Despite the caribou’s wide habitat range, our results showed that for many bird species caribou is unlikely to be a good umbrella, and alternative conservation approaches will need to be considered. This is especially true for wetland, grassland, deciduous and mixedwood forest specialists. For conifer specialists, caribou is likely to play a better role as an umbrella species.

The potential value of caribou as an umbrella for landbirds varies depending on the landbird species considered and their habitat preferences. From Micheletti et al. (2023).