Browsing Journal of Range Management, Volume 40, Number 1 (January 1987) by Subjects
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Crude Terpenoid Influence on Mule Deer Preference for SagebrushSamples of current year's growth of leaves and stems were collected in February 1983 from basin big sagebrush (Artemisia tridentata Nutt. tridentata), Wyoming big sagebrush (A.t. wyomingensis Beetle and Young), mountain big sagebrush (A.t. vaseyana [Rydb.] Beetle), and black sagebrush (A. nova Nels.) on a mule deer (Odocoileus hemionus hemionus) winter range near Gardiner, Montana. Samples were from both lightly and heavily used plants (form classes) within each taxon. Crude terpenoids were separated into 3 groups: headspace vapors, volatile, and nonvolatile crude terpenoids. Compounds in each group are thought to stimulate the sensory organs of mule deer. Individual compounds were identified and quantified for comparison with preference ranks among taxa and between utilization form classes. Seven compounds were selected by discriminant analysis as indicators among the 4 taxa, with methacrolein + ethanol, ρ-cymene, and the sesquiterpene lactones the most probable preference determinants. Seven other compounds were found useful for separating plants within taxa into form classes. Chemical differences between the 2 form classes, however, were less distinguishable than were those among the 4 taxa.
Seasonal Diets of Camels, Cattle, Sheep, and Goats in a Common Range in Eastern AfricaAlthough there have been several reports on the food habits of domestic herbivores in various semiarid regions of the world, there has been no previous report on the partitioning of forage resources by camels (Camelus dromedarius) and sheep (Ovis aries), goats (Capra hircus) and cattle (Bos indicus) using a common range. In the semiarid region of northern Kenya, the seasonal exploitation by these herbivores resulting from herding by the nomadic Rendille pastoralists makes the system for management of these rangelands very complex. Information on the food habits of animals utilizing a common range is important in offering a basis for assessing the usefulness of the range components to the animals. Consequently, food habits information becomes an important tool in making management decisions. Camels were predominantly browsers while cattle were predominantly grazers. Sheep and goats were intermediate feeders. Cattle browsed most during the 'green' season when the browse shoots were most abundant and easiest for their large mouth parts to harvest. Camels grazed most during the very dry season when most trees and shrubs had shed their leaves. The observed variations in food habits among the 4 herbivores suggest that they may require different management to obtain optimum production.