How Does an Elephant Use its Trunk?

An elephant lifting its trunk to its mouth as it drinks.
An elephant lifting its trunk to its mouth as it drinks. Photo © Johan Swanepoel / Shutterstock.

The trunk of an elephant is a muscular, flexible extension this mammal's upper lip and nose. African savanna elephants and African forest elephants have trunks with two finger-like growths at their tip; the trunks of Asian elephants have only one such fingerlike growth. These structures, also known as proboscides (singular: proboscis), enable the elephants to grasp food and other small objects, in the same way that primates use their flexible fingers.

All species of elephants use their trunks to strip vegetation from branches and to pull grass from the ground, at which point they shovel the vegetable matter into their mouths.

To relieve their thirst, elephants suck water up into their trunks from rivers and watering holes--the trunk of an adult elephant can hold up to ten quarts of water! As with its food, the elephant then squirts the water into its mouth. African elephants also use their trunks to take dust baths, which help to repel insects and guard against the harmful rays of the sun (where the temperature can easily exceed 100 degrees Fahrenheit). To give itself a dust bath, an African elephant sucks dust into its trunk, then bends its trunk overhead and blows the dust out over its back. (Fortunately, this dust doesn't cause the elephant to sneeze, which one imagines would startle any wildlife in its immediate vicinity.)

Besides its efficiency as a tool for eating, drinking and taking dust baths, the trunk of an elephant is a unique structure that plays a fundamental part in this animal's olfactory system.

Elephants point their trunks in different directions to sample the air for scents, and when swimming (which they do as rarely as possible), they hold their trunks out of the water like snorkels so they can breath. Their trunks are also sensitive and dexterous enough to enable elephants to pick up objects of various sizes, judge their wieght and composition, and in some instances even to fend off attackers (the flailing trunk of an elephant won't do much damage to a charging lion, but it can make the pachyderm seem like more trouble than it's worth, causing the big cat to seek out more tractable prey).

How did the elephant evolve its characteristic trunk? As with all such innovations in the animal kingdom, this structure gradually developed over tens of millions of years, as the ancestors of modern elephants adjusted to the changing requirements of their ecosystems. The earliest identified elephant ancestors, like the pig-sized Phiomia of 50 million years ago, had no trunks at all; but as competition for the leaves of trees and shrubs increased, so did the incentive for a way to harvest vegetation that would otherwise be out of reach. Essentially speaking, the elephant evolved its trunk for the same reason the giraffe evolved its long neck!