How Do Elephants Use Their Trunks? Smelling, Drinking and More

What is an elephant’s trunk?

The trunk forms in the unborn calf when the nose and upper lip grow together and stretch forward. In large adults it can be about 2 m (6.6 ft) long. Inside are two nostril tubes running all the way from the tip to the skull, wrapped in muscle, nerves and blood vessels.

There are no bones in the trunk. Instead it works as a “muscular hydrostat”, like a human tongue or an octopus arm: muscles running lengthwise, around and across the trunk squeeze against each other to bend, twist, stretch and stiffen it. Older books often say the trunk has about 40,000 muscles; detailed counts now put the number of separate muscle bundles, or fascicles, at up to about 150,000.

The trunk is also packed with nerves, and short whiskers along its length, especially near the tip, help the elephant feel what it is touching.

Smelling

The trunk is first of all a nose, and elephants have one of the best senses of smell of any animal. African elephants carry around 2,000 genes for smell receptors, more than any other mammal studied so far and roughly five times as many as people.

Elephants lift and wave their trunks to catch scents on the wind, sniff the ground for the trail of their family, and follow smells of water and ripe fruit over long distances. They can also tell people apart by smell. A bull checks whether a female is ready to breed by touching her urine with his trunk tip and transferring the scent to a special organ in the roof of his mouth.

Drinking, bathing and dusting

Elephants do not drink through their trunks like a straw. They suck water partway up the trunk and then curl it into the mouth and squirt the water in. An adult Asian elephant’s trunk holds about 8.5 liters (2.2 US gal), and a thirsty adult may drink 80–200 liters (21–53 US gal) a day.

A 2021 study filmed African elephants at Zoo Atlanta and found that they can widen their nostrils to hold more water and suck it up at about 3.7 liters (1 US gal) a second. During a strong inhale, air rushed through the trunk at more than 150 m/s (490 ft/s), nearly 30 times faster than the air in a human sneeze.

The same trick is used for bathing. Elephants spray water over their backs to cool off, then often throw dust, mud or sand on top, which dries into a crust that protects the skin from sun and insects.

Eating

The trunk is the elephant’s hand. It wraps around bunches of grass and tears them up, pulls leaves and fruit from branches up to about 6–7 m (20–23 ft) high, strips bark and digs for roots. Elephants also kick at clumps of grass with their front feet to loosen them before picking them up.

Because an elephant may eat up to about 150 kg (330 lb) of plants a day, the trunk is busy for most of its waking hours. For more on what goes into it, see What do elephants eat?.

One finger or two? African vs Asian trunks

The trunk tip is where the two kinds of elephant differ most:

The Asian elephant relies more on curling the trunk around food, while the African bush elephant can pluck small items with its two tips like a pair of tweezers. Both can pick up something as small as a coin. The other differences are covered in African vs Asian elephant.

Greeting, communicating and fighting

Elephants use their trunks to touch each other constantly. Friends and relatives greet by placing the trunk tip in each other’s mouth or on the face, and mothers guide and reassure calves with the trunk. A raised, curled trunk often signals excitement or alarm, and a trunk tossed in the air can be a threat.

The trunk also shapes sound. Elephants trumpet through it, and some low rumbles resonate in it. Young bulls wrestle by twining their trunks and pushing, and adults use the trunk to push, slap or block during serious fights.

Snorkeling and other surprising uses

Elephants are good swimmers. When crossing deep rivers they hold the tip of the trunk above the surface like a snorkel and breathe while almost fully submerged.

Other uses include:

• Lifting heavy loads. Adults can carry logs and branches weighing a few hundred kilograms.
• Tool use. Elephants hold branches in the trunk to swat flies or scratch themselves.
• Digging for water. In dry riverbeds they dig with feet and trunk, then suck up the water that seeps in.
• Handedness. Many elephants prefer to curl the trunk to one side when grasping, much as people favor one hand.

How calves learn to use their trunks

A newborn calf cannot control its trunk well. For the first few weeks it flops around, and calves sometimes trip over it or suck on it for comfort. Calves drink milk with the mouth, not the trunk.

By a few months old, a calf can pick up objects and is starting to gather plants and water. It takes most of the first year to master fine trunk movements, learned largely by watching and copying older elephants.