by Annette J Beveridge
An elephant’s trunk is an incredible appendage growing 6-8 ft in length and weighing approximately 140 kg. It should be considered a combination of body parts set in one as it forms the upper lip and an extension of the nose. The nostrils run all the way through the length of the trunk. At the tip of an African elephant’s trunk, you can see the equivalent of two prehensile fingers. This is a proboscides which enables them to grasp and to pick up even the smallest of objects. Asian elephants are different in that they have just one prehensile ‘finger’ at the tip. This is known as a proboscis.
Muscles and usage
There are no bones or joints in the trunk, but they have 40,000 muscles providing flexible movement. By contrast, humans have 600+ muscles within the whole of the body. Elephants use their trunks for multiple tasks, stretching high up into the trees to strip vegetation from branches, or gently rubbing at an itchy part of the body. They use it to satiate thirst too by drawing up to 4 litres of water into the trunk and then, releasing a little water at a time into the mouth.
Elephants must protect their skin from the sun, so they spray mud and dust over themselves which also helps to repel insects. The trunk can act as a snorkel if the elephants move into deeper water or choose to submerge themselves.
The trunk is vital for their survival.
Elephants have an acute sense of smell considered greater than that of a bloodhound. Elephants lift the trunk into the air to scent danger. There are chemical and olfactory sensors (millions of receptor cells) within the upper nasal cavities and these enable the elephant to be sensitive to vibrations from far off herds. They can also detect thunder rumbling in the distance or locate water even in the driest of seasons.
African elephants make wide-ranging sounds – from rumbles at a very low frequency to snorts emitted at a higher frequency. Sound is produced as air expelled from the lungs is passed over the vocal chords or larynx. The moving air causes the vocal chords to vibrate at a particular frequency.
By lengthening or shortening the vocal chords, the frequencies change. Sound is created by a column of air that vibrates in a resonating chamber/vocal tract. The sounds are modified or extended depending how the elephant holds the trunk, tongue, mouth, larynx or pharyngeal. Low frequency rumbles may go through the trunk or can be produced with the mouth open, however, if the trunk is used, the sound is flatter and lower.
The trunk is used for play fighting with other elephants however, they do not typically use the trunk if in serious combat. You can decipher an elephant’s intent by monitoring how the trunk is held. If an elephant is starting to charge, and the trunk is tucked under, then you can ascertain that the elephant is serious. If the trunk is stretched out in front of it, the elephant is potentially bluffing.
When a calf is born, they have little control over their trunks. In the first few months, the trunk swings around in an uncontrolled way. Calves often suck the trunk for comfort. Think how children might suck their thumb to reassure themselves. This trunk sucking helps them to begin to control this unruly appendage. As the calves reach 6 to 8 months, they start to use the trunk to feed and drink. At 12 months old, the trunk is sufficiently under control to even fling mud or sand around.
As the calf develops, they use the trunk to taste the pheromones from other elephants. They may touch faeces or urine and pop the trunk into the mouth to identify the odour. A mother elephant also uses her trunk to comfort the calf. They do this by wrapping their trunk around the calf’s belly or back leg or may touch the neck or shoulders tenderly. Elephants also pet themselves with their trunk as a way to reassure themselves.
Elephants’ trunks developed over many millions of years. One of the very first ancestors to the elephants was only the size of a pig. This animal did not even have a trunk. As the environment changed, elephants had to adapt to reach their food.