Table of Contents
Fire Ecology, 2016
Volume 12, Issue 3
Short-Term Impacts of Fire-Mediated Habitat Alterations on an Isolated Bighorn Sheep Population
Authors: Justin G. Clapp and Jeffrey L. Beck
Habitat alterations may improve and expand wildlife habitats, and bolster waning wildlife populations. We used global positioning system (GPS) locations to monitor 38 bighorn sheep (Ovis canadensis
Shaw) that were translocated to the Seminoe Mountains, Wyoming, USA, in 2009 and 2010, and 24 bighorns captured in 2011 to investigate short-term impacts of prescribed fires and wildfires that covered ~24 % of the study area in 2011 and 2012. We quantified home range distributional changes, resource selection, and survival of bighorn sheep from 2009 to 2013. Although bighorns expanded home ranges and increased proportional use of fire-treated areas, there was no overall selection for fire-treated areas. Bighorn survival decreased by over 30 % after fires in 2012 that were accompanied by severe drought. Prescribed fires conducted under favorable conditions (2011) induced potentially positive bighorn responses including high survival and increased use of treated areas. Fires during drought conditions were more widespread with little vegetative response (2012) and coincided with increased bighorn mortality in spring 2013. Dead bighorns with poor body condition had high home range overlap with burned areas. We suggest that large fires coupled with unfavorable weather conditions rendered bighorns unable to access adequate forage to meet nutritional requirements. Because impacts of fires on bighorn populations are highly dependent on ensuing vegetative recovery, consideration should be given to the timing, extent, and spatial coverage of prescribed fires. Therefore, we recommend conducting prescribed fires before bighorn reintroductions, or conducting prescribed fires on a relatively small scale and on a rotational basis to avoid reducing foraging options.
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