Influence of prescribed fire on Stone's sheep and Rocky Mountain elk: Forage characteristics and resource separation.

For over 30 years prescribed fire has been used as a management tool to enhance ungulate habitat in northeastern British Columbia (BC), where up to 7,800 ha are burned annually. Yet relatively few studies have quantified the role of fire on both plant and animal response, and whether it enables competition between focal grazing species such as Stone's sheep (Ovis dalli stonei) and elk (Cervus elaphus). Seven prescribed burns (150-1,000 ha) were implemented in the spring of 2010 and 2011 in the Besa-Prophet area of northern BC. I examined the response of Stone's sheep and elk to seasonal changes in forage quantity and quality by elevation in treatment versus control areas. I monitored vegetation and fecal pellet transects at a fine scale and used Landsat imagery, survey flights and GPS telemetry at a landscape scale. By one year after burning, forage digestibility and rates of forage growth were higher on burned than unburned areas. At both scales Stone's sheep and elk always used burns more than control areas in winter. Stone's sheep and elk appeared to partition their use of the landscape through topography and land cover. Increased use of burned areas suggests that prescribed fire enhanced habitat value for grazing ungulates in the short-term. By altering animal distributions, however, the use of prescribed fire has the potential to change complex predator-prey interactions in northern BC. --Leaf ii.