Herbivore

A herbivore is an animal whose diet consists chiefly of plants: grass, leaves, branches, roots, fruits and seeds. The term is translated into other languages as 'herbivore' in English and 'عاشب' in Arabic. It is the opposite of the carnivore, while an animal that eats both is called an omnivore.

Herbivores occupy the lower levels of the food chain in an ecosystem: they obtain energy from plants, and in turn become food for carnivores. Because plants contain cellulose, which is difficult to digest, herbivores have specialized digestive systems and teeth adapted for this purpose.

Body structure and digestion

Many herbivores have broad, flat molars for grinding leaves and grass, while their front teeth cut vegetation. Cellulose cannot be digested by the animal's own enzymes alone; bacteria and microorganisms in the digestive tract assist through fermentation.

There are two main types: those with a four-chambered stomach such as camels, cattle, sheep and goats—which regurgitate and re-chew their food (ruminants)—and those that perform fermentation in the lower part of the digestive tract, such as horses, donkeys and rhinoceroses.

Feeding specializations

Herbivores are classified according to what they eat. Grazers feed on grass at ground level, such as cattle and goats. Browsers feed on trees and shrubs, such as camels and giraffes. Some are specialized in eating fruits, seeds or nectar; certain birds and insects are also herbivorous.

Role in ecosystems

Herbivores shape how vegetation can grow in an area. Overgrazing can reduce grass cover and expose soil to wind erosion, while moderate grazing can help new plants grow. They also disperse seeds to other locations. Somali pastoralism—based on camels, cattle, sheep and goats—depends entirely on pasture and browse.