Wildfire effects on home range size and fidelity of boreal caribou in Alberta, Canada

Abstract

Wildfire can rapidly alter the forage availability for boreal ungulates such as woodland caribou ( Rangifer tarandus caribou Gmelin, 1788). Since fire decreases available lichens, a crucial food source for caribou, it may be an important determinant of caribou range use and demography. Here we examined whether wildfire affected range use, habitat selection, and basic demographic variables of boreal caribou in three regions in northern Alberta, Canada. Contrary to expectations, caribou showed no change in home range sizes nor did they shift their home ranges in the years following fires, despite having up to 76% of individual home ranges burned. Within home ranges, caribou preferred stands >50 years old and avoided stands <50 years old, but the extent of home range burned did not affect habitat selection in the year after fire. Although fire does not seem to directly affect the spatial distribution of Alberta caribou, the generation of younger seral stages may affect how caribou distribute within their annual ranges. However, this did not appear to affect population demographics, as fire did not affect annual mortality or fecundity. Boreal caribou in Alberta may be resilient to the effects of fire owing to large home ranges.