Grasses make up
most of an elephant’s daily diet. This means that elephants travel
on most days to find clearings at the edge of forests where they
spend hours gathering grasses with their trunks. After ripping off
a bunch of stems, they typically swirl it in the air and pound it on
the ground before putting into their mouths. Presumably this rids
the plant material of unwanted dirt and debris.
photo M. Noonan
elephants repeatedly swirl and pound each bunch of grass before
herbivores, elephants depend on beneficial bacteria that produce
necessary enzymes inside their digestive systems—enzymes that are
able to break down the cellulose in plant cells and convert it to a
source of energy for the elephants. In other words, when an
elephant eats grass it is really feeding the bacteria in its
digestive system, and these bacteria in turn feed the elephant.
Micrograph of elephant fecal matter showing numerous beneficial
cannot maintain good health on grass alone. Like humans, they need
a minimal level of protein in their diet, and grasses are a poor
source of protein. This means that an elephant must also spend part
of each day in search of plants that are in their active growing
stages, plants that are producing new leaf buds and growing stems
that have high levels of protein. Additionally, they must find
plants that will provide them with a minimum level of other
necessary nutrients (calcium, magnesium and so on) that are
essential to their health.
photo M. Noonan
Elephants move daily into, and out of, grasslands
To satisfy all of
its needs, an adult elephant consumes about 300 pounds of plant
material per day, and it moves about 10 miles per day, seeking out
and eating small amounts of many different plant species.
Naturalists have counted 112 different plant species that elephants
consume at one time or the other throughout the year.
It is not necessary
to infer that elephants understand their nutritional needs in any
conscious way. It is just that they have been built with a taste
for certain plant species, and that is enough to drive them to seek
out and gather in the appropriate foods.
Elephants live very
long lives and they appear to remember locations of desirable plant
species from year to year, and maybe even from decade to decade. By
leading the group from place to place, matriarchs evidently pass
this knowledge down to their daughters and grand daughters.