Bamboos, Bark, and Bananas
The Diet of a Megaherbivore
The feeding habits of the largest land mammals have naturally attracted a lot of attention, if only for the sheer quantity and variety of plants they consume and the impact they make on their habitats. Both in Africa and in Asia, there have been numerous studies of the foraging ecology of the elephant. Given the diversity of habitats in which elephants are found across the two continents, we can naturally expect considerable variation in the types and parts of plants they consume. Yet, we must search for commonality amid the myriad patterns of foraging behavior recorded. Can the elephant's feeding strategies throughout its range be explained by a simple set of rules?
An animal's feeding behavior is fundamentally explained by its anatomical and physiological adaptations, products of its evolutionary history. Among mammalian herbivores, structures of the teeth and of the gastrointestinal tract are obviously important determinants of plant types eaten. Their ability to degrade cellulose in the plant cell wall through microbial symbionts for obtaining energy is closely related to the structure of the gastrointestinal tract. Body size exerts a great influence through its physiological consequences, such as metabolic rate. The sexes may have differing nutritional requirements or may use habitats in a different manner; females and young may have greater need to avoid predators, for example. In the case of the elephant, the very large body size imposes special constraints on its feeding ecology. At a more proximal level, the food choices of a herbivore will depend on what is available. The