Dietary choice determinism for grazing herbivores : principal theories

Abstract

The objective of maintaining adequate grassland requires a better understanding of the conditions affecting the dietary choices of herbivores. The studies in this area have long been based on the Optimal Foraging Theory, which states that an animal’s feeding decisions are dictated by its will to maximize its energy balance. In order to better explain the variety of observed diets, however, other approaches have been suggested. These are largely inspired by the nutritional constraints of herbivores. The morpho-physiological characteristics of the animals largely explain the different choices between species. In each species there is evidence that learning early in life, learning from mother, and learning the consequences of nutritional choices from postingestive feedback all play a role in the acquisition of eating habits and explain both a certain nutritional wisdom and the flexibility in the observed behaviour.