Review of availbale techniques for determining the diet of large herbivores from their faeces [Revue des techniques disponibles pour déterminer le régime alimentaire des herbivores d'après leurs fèces].

Résumé

Accurate determination of herbivore diets is normally of great interest in most ecological studies. We review two techniques of diet determination, based on fecal analysis, that had been attracted much attention because of its suitability for wild animals. The micrographic technique is based on the recognition of indigestible forage fragments, maily epidermis and cuticles, under the microscope. The alkanes technique is based on the recognition of alkane pattern (saturated hydrocarbonsof the cuticlar plant wax) from herbivores faeces. The advantages of both techniques include ease of sampling and, that they do not interfere with animal behaviour or not imply its death. The main disadvantage of the micrographic technique is the possible under or overestimation of the consumed plant species frequencies because of the effect of differential digestion. The main problem of alkane technique is that, for the moment, only diets with few components can be determined. We discuss the possibilities for improving both techniques and we suggest their complementarity as a mean of increasing its accuracy.