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

Abstract

All rights reserved INFORMATION TO ALL U SER S The quality of this reproduction is dep en d en t upon the quality of the copy submitted.In the unlikely even t that the author did not sen d a com plete manuscript and there are m issing p a g es, th e se will be noted. Also, if material had to be rem oved, a note will indicate the deletion. Landsat imageiy, 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 unbumed areas. At both scales Stone's sheep and elk always used bums more than control areas in winter. UMIStone's sheep and elk appeared to partition their use o f the landscape through topography and land cover. Increased use o f 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.

Resource separation by mountain ungulates on a landscape modified by fire

“…Grouping behavior may help as an anti-predation strategy because larger groups increase the ability to detect predators (Mao et al 2005, Geist 1971, Heard 1992, even though they may be encountered more frequently by predators (Hebblewhite and Pletscher 2002). Concurrent with our study, Sittler (2013) recorded the distribution of groups of elk and Stone's sheep on burned and unburned areas in the GBPA during monthly fixed-wing flights. The largest groups of both species were observed in winter on prescribed burns.…”

“…Prescribed fires decrease shrub cover, opening up areas with increased visibility (Risenhoover and Bailey 1985), and increase the quality and quantity of forage for grazing ungulates (Sachro et al 2005, Van Dyke and Darragh 2007, Sittler 2013. The GBPA, with no industrial access or resource extraction activities, provided a rare opportunity to study the impacts of fire on ungulates without the influence of other confounding, cumulative anthropogenic impacts.…”

“…Since 1980, 138 areas have been intentionally burned, often repeatedly, in the GBPA (Fig. 1;Sittler 2013). Prescriptions for burning are identified and prioritized by the Northeast BC Prescribed Burn Council based on the potential to increase forage quality and quantity for ungulates on winter ranges.…”

“…Winter and latewinter ranges were most associated with burned areas, with burns comprising an average of 26% and 30% of these seasonal ranges for Stone's sheep and elk, respectively. Recent burns provide access to higher quality forage in winter and are usually associated with earlier green-up than surrounding areas in spring (Sittler 2013); older burns usually provide increased forage quantity (Sachro et al 2005, Van Dyke andDarragh 2007). Such changes in nutritional value and forage production also enable increased foraging efficiency by ungulates (Hobbs and Spowart 1984).…”

“…Small ungulates tend to rely more on forage quality than larger ungulates, which select for forage quantity in burned patches (Sensenig et al 2010). New burns, with short-term increases in forage quality (Allred et al 2011, Sittler 2013, have lower forage biomass until at least 1 year after burning, after which forage biomass begins to increase and remains higher for several years (Sachro et al 2005, Van Dyke and Darragh 2007, Sittler 2013. During our study, collared animals had access to over 138 different burns ranging in age from 0 to 31 years old in the GBPA.…”