Slope Use by Cattle, Feral Horses, Deer, and Bighorn Sheep

Abstract

Parferns ofslope urilizarion by cattl (Bos spp.), feral horses (tqaus calallrr), Rocky Mountain nule deer (Odocoileus hemionus hemionus), and California bighorn sheep (Oais canadensis caLifuntdnd) were monitored ro compare their distributions ro rhe topographic compositions of iheir respective habitals.The hypothesis lhal each species utilized slope ciasses in proportion ro rhe ropographic cornpositions of thei.respective habitats {as rejected (P < 0.01).Bighorn sheep aciivilies {re nol impaird by slopes of up to 80%.Cattle, horses, and deer demonstrated negativ cur linear responses to increasing slope wirh initial sire avoidance exhibired on 20, 30, and 40% slopes, .spectively.Vhere large expanses of level topography were available, carde and horses made less use ofsteep slopes than thir counterparts inhabiting more rugged trrain.Thse daia demonslrat that cattl, horses, and der should not b xpectd to nake randon us of fotrge rsources in rugged terrain.lntroduction An awareness of the distribution and movement patterns of large herbivores is particularly valuable to managers charged with allocating resources or assessing the impacts of utilization by large herbivores.The arrangement of food, water, and shelter, and their concuirent interactions ryith topographic features obviously influences the distribution of animals and their simultaneous use of an area's resources.Slope gradient may also be a major determinant of herbivore distribution in rugged terrain.With the exception of cattle (Bos spp.), few data are available describing the upper limits of slope use by large herbivores.