Research Brief

African elephant trunks reach up to 7 feet in length, while Asian elephant trunks reach up to 6 feet. The transcript's claim that elephants have "really, really, really long trunks" is accurate but dramatically understates the trunk's significance. The trunk contains an estimated 100,000 muscles and tendons, giving it extreme flexibility and strength, with finger-like projections at the tip capable of fine motor skills. Recent research using CT scans on a baby elephant trunk revealed almost 90,000 surprisingly tiny bundles of muscle fiber, representing the most complex musculature known in the animal world.

African elephants have two triangular protrusions at the trunk tip that act as fingers for pinching and picking up objects, while Asian elephants have just one trunk 'finger' and tend to grasp objects with their whole trunk. Elephant trunks can effortlessly hoist weights of up to 340 kilograms and conversely pluck individual leaves with precision. An adult Asian elephant can hold up to 8.5 liters of water in its trunk, which is sprayed into the mouth for drinking and onto the back to keep cool. The trunk functions as a muscular hydrostat—an organ without bones that maintains constant volume while changing shape—moving through finely controlled muscle contractions using three basic movements: bending, twisting, and longitudinal stretching or retracting.

Whiskers grow all along the trunk and are particularly packed at the tip, contributing to its tactile sensitivity; unlike those of many mammals, elephant whiskers do not move independently to sense the environment. An elephant's trunk has the highest number of odour-detecting genes discovered in mammals so far, with millions of receptor cells in the upper nasal cavities that surpass even a bloodhound's nose in olfactory sensitivity. Research shows that elephants evolved strategies reducing the biomechanical complexity of their trunk: complex behaviors emerge from a finite set of basic movements, and the trunk tip velocity obeys a power law with its path curvature, similar to human hand drawing movements. This research has direct applications for soft robotics, with companies already developing trunk-like manipulators based on elephant trunk anatomy.