Meeting Abstract

P3-45   -   Asymmetric Elongation of Elephant Trunks Boyle, MA*; Schulz, AK; Hu, DL; Georgia Institute of Technology; Georgia Institute of Technology; Georgia Institute of Technology mboyle@gatech.edu

The elephant trunk is one of the largest versatile boneless appendages, dwarfing similar muscular hydrostats like octopus tentacles and chameleon tongues. With nearly infinite degrees of freedom, the trunk can be bend, twist, and stretch to lift heavy objects or reach for something far away. We know that an elephant can lift several hundred pounds with its trunk, but just how far can it reach? Using a high-speed camera, food incentives, a black tarp, and a little bit of duct tape, we found that elephant trunks can extend up to 125% of their resting length, a small percentage compared to the chameleon tongue’s 1000%. Seemingly restricted by their massive size, elephants may employ unique strategies to accomplish complex signature movements, including reaching. By observing high-speed videos of reaching trunks, we determine asymmetric relationships between trunk morphology and elongation mechanics. Not only does the trunk behave like a telescoping pole, extending one segment at a time, but the dorsal section stretches more than the ventral section. We discuss how elephant trunks stretch section by section and why the trunk’s skin is as important as the muscles when reaching for faraway objects.