It’s no mystery that elephants use their versatile trunks to grab food and stuff it in their mouths; this behavior is frequently seen in nature as the creatures reach into trees to grab branches or leaves, but not all types of food can be picked up with the tried and true ‘grab’ technique.
Image Credit: Atlanta Zoo
A team of curious researchers from Atlanta Zoo, the Georgia Institute of Technology, and the Rochester Institute of Technology wanted to learn more, so they filmed an adult elephant at Atlanta Zoo as they fed it different types of food comprised of various shapes and sizes. Their findings have been published in the Journal of the Royal Society Interface.
The researchers’ elephant-centric smorgasbord encompassed a variety of items, including carrots and rutabagas sliced to various sizes. But perhaps the most captivating thing on the menu was the bran, which sports a near-powder consistency.
Astonishingly, upon feeding the differently-sized foodstuffs to the elephant, it formed a ‘joint’ with its trunk and compressed the smaller food bits into solid masses that could be more easily picked up with the trunk and consumed.
"It seems counterintuitive that you put more weight on something that you're trying to pick up, but the reason that makes sense is that when you push down on this food, because it's particulate, it forces all the food to squeeze together even more," elucidated study co-author Scott Franklin, a scientist at RIT.
"The more tightly the food is squeezed together, the more likely the friction between them will be enough to allow you to pick it up."
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The researchers placed the food on a force plate before feeding it to the elephant, which allowed the researchers to discern how much force was necessary for the compression. They found that the joint shape in the trunk differed depending on the force exerted by the elephant; the more force there was, the longer the joint, perhaps for additional leverage.
The findings are important not just for understanding elephants, but also for learning more about the mechanisms behind these techniques such that we can replicate them in robotic applications for real-world use.
"It is very difficult to develop a gripper that is flexible enough to pick up a variety of objects, for example, a single pen or a pile of pens, or a cube of Jell-O," Franklin added.
"The elephant trunk is a single thing; it doesn't change shape at all, but it is able to pick up food of different sizes, weights, and masses, so the idea is that this will give us insight and information into how nature has solved this problem of how to pick up multiple things and then we can try to reproduce it."
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It’s certainly fascinating to have learned how elephants pick up near-powder-like substances, but it should be even more interesting to observe how this research inspires future advancements in technology.
Source: Rochester Institute of Technology,
