African elephants are the largest elephants in the world and they spend three quarters of their time eating. An elephant can put away more than 400 pounds of vegetation a day, grazing on brush, grasses and trees – whatever is available. They are herbivores and use their tremendous molars to grind plants and extract nutrition. But they cannot digest cellulose, which is most of the plant, so they have to eat massive amounts every day to survive.
The Acacia tortilis, also known as the umbrella tree, is an iconic African symbol. Its spreading branches against the grasslands of the savanna are an instant photo opportunity. It is also a very tasty elephant meal although elephants prefer the seedlings of the tree and will consume all that they can find. The trees give elephants a higher amount of crude protein and fiber than grasses supply -- protein content can be twice as high in tree browse as it is in grasses -- and acacia are a valuable fallback during the dry season when other plants are less available. Elephants look for forage that is dense in nutrition when food sources are slim, and acacia are reliable nutritional reserves.
The sausage tree puts out long, heavy, sausage-shaped fruit that falls from the tree and rots as its seeds disperse. Elephants find the fruit of the sausage tree delectable, although it is a rare treat because the trees are not very plentiful in the Serengeti. Elephants push their heads against the bark of the tree, jarring it, and then wrap their trunks around the trunk of the tree. They shake the sausage tree until the fruit falls to the ground where it is easily retrieved for eating. They may uproot the whole tree before consuming the fruit. But they will eat the leaves as well, and help to disperse the seeds of the tree as they wander the savanna in search of the next meal.
A baobab gets pretty aggressive treatment from elephants. They will tusk the bark of the tree to remove it in big strips and get at the juicy pulp beneath it. Elephants are particularly drawn to the moisture reserves of the baobab during dry season. But elephants also eat the bark, the leaves and the fruit. This is important because a baobab can end up sacrificed for elephant brunch but the hungry mammals have dispersed the seeds, leading to new growth. The vitamin C in one baobab fruit equals the vitamin C in four oranges; the seeds contain a large amount of protein and the leaves are high in calcium.
Grasses are the fast food of elephants and anywhere from 30 to 60 percent of their diet is savanna grass. The grasses are sweet and require very little effort to consume, unlike the bark of trees. Long grass is the easiest to fill up on but most of the time the elephant has to take whatever it can find. Vanishing habitats and the frequent fires that burn off the savanna grassland can make for some lean times in the elephant's constant search for enough food. Red grass is a tall plant that grows in clumps and can spread out to cover a large area. Pan dropseed is a shorter grass that is vigorously grazed. Porkbush is an evergreen shrub with tart, sour, succulent leaves that elephants munch from the top down, allowing the plant to spread out close to the ground, flower and release its seeds.