Elephants: Proboscidea

Elephants are herbivores, plant eaters, who eat a wide range of various plant types, including grasses, trees, vines, and shrubs. They consume between one hundred and five hundred species of plants, and eat everything edible on each plant, including twigs, bark, flowers, roots, bulbs, leaves, and shoots. Tree bark is favored because it provides essential minerals and other nutrients.

What elephants eat depends on the season. During the rainy season, 50 to 60 percent of an elephant's diet is made up of new grasses. As those grasses dry out in the African and Asian sun, the elephants eat more fruit and shrubs, which account for about 70 percent of their diet. Bamboo is a staple, basic food, for elephants residing in the forests of Asia. Elephants in the rainforests of Africa and Malaysia eat more leaves and fruits.

Elephants eat 220 to 660 pounds (100 to 300 kilograms) of food daily. Anywhere from twelve to eighteen hours of each day is spent eating. Where elephants live determines their behavior in terms of food gathering. Elephants in forest areas travel slowly, eating plants as they cover about 3 miles (5 kilometers) each day. Elephants who live in woodlands and grasslands spend the hottest parts of the day in the wooded areas and graze in the grassland as the temperatures cool down. Elephants drink up to 53 gallons (200 liters) of water each day in hot weather. When water is hard to find, they dig holes in dried-up streams or lake beds until water seeps in, then they suck it up through their trunks.

An elephant's trunk is a major eating utensil. Smaller items are plucked or picked up with the trunk while larger items like branches are torn away from the tree by putting the trunk around them and twisting. To reach the top of trees, elephants stand on their hind legs, which give them a total reach, combined with the stretch of the trunk, of 26 feet (8 meters). Elephants have also been observed pushing over and uprooting trees. The trunk is also important for drinking and is used like a straw. The elephant sucks water up its trunk only until it can be squirted into its mouth. Water never reaches the elephant's nose. An elephant's trunk can hold 2.2 gallons (8.5 liters) of water. The only time elephants eat without the use of their trunks is when they are nursing from their mothers.

Tusks are also useful for eating. They can strip bark from trees, dig for roots and water, and scrape salt and other nutrients from soil or rock. Food is chewed by grinding the lower jaw against the upper jaw, using a forward and backward motion. The molars, back teeth, of an elephant are flat-topped, each one independent from its own root. The molars are held together by a cement-like material and form blocks of enamel and dentin about 11.8 inches (30 centimeters) long. As each set wears down, another larger set moves forward to replace it. Elephants have a total of six pairs of teeth blocks, each weighing up to 8.8 pounds (4 kilograms). The final pair emerges into place around forty years of age and takes about twenty years to wear out. At that time, the elephant dies of a combination of starvation, malnutrition, and old age.

Because elephants do not digest food effectively, only about 40 percent of food by weight is used. The intestine is 115 feet (35 meters) long in comparison the human adult intestine is about 12 to 13 feet (3.7 to 4.0 meters) long. When the elephant is full the intestine weighs up to a ton (0.9 metric tons). An elephant expels an average of 220 pounds (100 kilograms) of feces daily.