Secrets of Elephant Trunks

Let’s do a little experiment. Find a small piece of food around you, about the size of a hard candy or an apple slice, and pick it up. How did you do it? I assume you used the thumb and index finger of your dominant hand. Some people use their thumb and middle finger too. Now find something much smaller, like bread crumbs or sunflower seeds. How do you most efficiently pick them up? Most likely by using the outside of your palm to sweep them into a pile and then use your whole hand to grasp the pile. Elephants do the exact same thing!

African elephants have two “fingers” at the tip of their trunk that allow for fine dexterity, fine enough to pick up a single blade of grass. They pick up small food items the same way humans do, but with far less force. Through collaboration with Dr. David Hu and Jianing Wu at Georgia Institute of Technology, researchers are able to determine the exact force exerted by humans and elephants when picking up objects of various size. Surprisingly, elephants are more delicate than humans are for picking up food items, but the trend is the same for both: As the food item gets bigger, the contact forced exerted to pick up the item decreases. Elephant are able to grasp delicate items, like tortilla chips, without breaking them.

The same research team is now examining the volume and capabilities of the elephant trunk by measuring the amount of water Tara and Kelly can suck up in addition to the velocity in which they suck up the water. They are testing this with glass aquariums to measure the amount of water and added chia seeds to measure the water movement and velocity. While the elephant trunk is a massive 200+lb appendage, it appears that it is full of secrets.

Stephanie Braccini, PhD
Curator of Mammals

http://www.sicb.org/meetings/2017/schedule/abstractdetails.php?id=580
http://www.sciencemag.org/news/2017/01/watch-elephant-pick-tortilla-chip-her-trunk-without-breaking-it