- Herbviores that eat mainly fruit are called frugivores. The ones that eat almost all leaves are known as folivores while the nectarvores feed on the nectar of flowers. Further classes of herbivores include the seed eating granivores, the palynivores that consume pollen, and the root-gobbling rhizophages. Xylophages dine on wood. This is not to say that all herbivores eat only specific parts of a plant, as many will gladly eat the entire thing.
- Herbivores need to chew their food in order for it to be processed by their digestive system. They have adapted to do this most efficiently in many ways. Sheep, for example, have large back teeth with wide surfaces and ridges that fit together tightly. The sheep will move its jaw from side to side and break the grass up between these teeth. Birds that eat only plants lack teeth in the conventional sense but have a crop in their digestive system that contains minute stones that grind up the plant matter they consume.
- Ruminants are herbivores that have two stomachs. The members of the deer family, such as moose and elk, are ruminants as are animals such as giraffes and cows. The ruminant herbivore will eat plants and the matter will go into their first stomach, called the rumen. When the animal has an opportunity, usually at night when it is at rest, it will bring the contents of the rumen back up into its mouth, chew it in a form known as cud, and then swallow it into the second stomach from where it makes its way to the digestive tract.
- Some non-ruminant herbivores need to eat large amounts of plants to survive. Zebras, hippos and rhinos are non-ruminants that need to eat often and in large quantities, since their digestive systems absorb nutrients from plants in a different way. By the time most of the plants they consume have been broken down, they have made their way past the part of the digestive tract that absorbs the nutrients, so these herbivores need to eat and eat and eat to make up for this shortcoming.
- The largest land animals that ever lived on earth were herbivores. They were dinosaur families known as sauropods, with huge bulky bodies and small heads on long flexible necks. They lived only on plants, eating on land and in the marshy swamps. These herbivores had to consume hundreds of pounds of plants each day to maintain their energy and body weight, which could be several tons.
