Effects of Prescribed Fire on Nutrition of Mountain Sheep and Mule Deer during Winter and Spring

Abstract

Prescribed burning elevated the concentration of protein and in vitro digestible organic matter (IVDOM) in winter diets of mountain sheep (O. canadensis) and mule deer (O. hemionus) feeding in grassland and mountain shrub communities. No effect of burning on ungulate nutrition was observed during spring. In both communities, the magnitude of treatment effects tended to depend on the month diets were observed. Effects of burning on diet crude protein persisted for 2 yr in both communities. Treatment effects on diet IVDOM lasted for 2 yr in mountain shrub, but were absent during the 2nd yr in grassland. Effects of fire on diet quality resulted from changes in ungulate diet selection rather than improvements in the quality of individual forages. Differences in the amount of green grass in ungulate diets accounted for much of the enhancement in diet quality. Prescribed fire can improve winter habitats for mule deer and mountain sheep.