Print PageThe Woodland Caribou (Rangifer tarandus caribou), Boreal Population, was listed as a species Threatened with the risk of extinction under the Canadian Species at Risk Act (SARA) in 2001. The Minister of the Environment must prepare a Recovery Strategy for this species under SARA that includes an identification of its critical habitat where possible. In 2008, Environment Canada published a report that provided a scientifically defensible description of critical habitat for boreal caribou. The critical habitat description assessed whether the current conditions of each of the 57 boreal caribou ranges in Canada where sufficient to allow populations to survive over the long-term. The range assessment was based on available population information and estimates of disturbance (fire and buffered human disturbance) which was shown to have a negative affect on boreal caribou recruitment. We describe a number of new analyses undertaken by Environment Canada since 2008 to refine the description of critical habitat for the species’ Recovery Strategy. These analyses focused on quantifying: 1) the relative impact of different disturbance types and their configuration, as well as other habitat types, on the assessment of current range conditions; and 2) future changes to range conditions given passive recovery of old disturbance and new disturbances created by fires.
Results/Conclusions
Our analyses indicated that calculating the percent of non-overlapping disturbance within a range when human disturbance was buffered by 500m captured some basic information about the effects of configuration of disturbance on caribou demography. Buffering had less of an impact on estimates of non-overlapping disturbance where disturbance was aggregated compared to areas where disturbance was dispersed. Overall, the 500m buffer appeared to adequately capture the ecological footprint of human development or zone of influence, defined as areas functionally lost to caribou due to their avoidance of habitats in proximity to anthropogenic disturbance. A number of candidate models were developed to assess the impact of different disturbance types and variation in habitat quality on caribou demography. Despite expanding the 2008 analysis, the results remained unchanged. The percent total non-overlapping disturbance (fire + human disturbance buffered by 500m) was the best predictor of caribou recruitment. These analyses were used to provide a 2011 updated current range assessment. The modeling of future range condition highlighted which ranges would require active management intervention to recover the populations therein to self-sustaining levels.
