• Influence of rest-rotation cattle grazing on mule deer and elk habitat use in east-central Idaho

      Yeo, J. J.; Peek, J. M.; Wittinger, W. T.; Kvale, C. T. (Society for Range Management, 1993-05-01)
      Elk (Cervus elaphus Linnaeus), mule deer (Odocoileus hemionus Rafinesque), and cattle (Bos taurus Linnaeus) distributions were determined year round from 1975-1979 on a rest-rotation grazing system established in steep mountainous terrain. Following implementation of the grazing system, cattle progressively used higher elevations and steeper slopes in each succeeding year. Elk preferred rested pastures during the grazing season (June-October) and avoided habitat frequented by cattle by using higher elevations and steeper slopes. Few mule deer used the allotment during summer, but during the winter, deer selected habitats grazed previously by cattle. Elk appeared to adjust to the grazing system by making greater use of pastures with cattle present, although preference for pastures without cattle continued.
    • Plant structure and the acceptability of different grasses to sheep

      O'Reagain, P. J. (Society for Range Management, 1993-05-01)
      Plant structure should be an important determinant of species acceptability to grazing ungulates functioning under various time-energy constraints. The acceptability of 9 grasses to sheep grazing a secondary grassland community in spring, summer, and autumn in South Africa was related to the following species attributes: plant height, leaf table height, tussock diameter, stemminess, percent leaf, leaf density, percent dry matter (DM), leaf tensile strength, and leaf crude protein (CP). Species acceptability over the grazing season was positively related to tussock diameter (P less than or equal to 0.05) but negatively related (P less than or equal to 0.01) to leaf tensile strength and DM. Discriminant function analysis successfully discriminated between species in different acceptability classes in summer (P less than or equal to 0.05) and autumn (P less than or equal to 0.01) using a combination of plant structure and leaf quality attributes. Correspondence analysis indicated that preferred species were generally short and nonstemmy and had leaves of low DM, low tensile strength, and high crude protein content. Conversely, avoided species tended to be tall and stemmy with a high leaf table height, and had leaves of high DM and tensile strength but low CP levels. It is concluded that, for sheep, acceptability is determined by a combination of plant structure and leaf quality attributes.