Chameleons are among the slowest moving reptiles. But their protruding eyes swivel independently for a 360 degree range, so they can look for prey in different directions at the same time. When a hapless insect victim is detected, both eyes focus on it to judge range and distance with superb accuracy.
• Ballistic Brilliance! The chameleon then launches its tongue, which is 1.5 times its body length, at speeds of 26 body lengths per second. That works out to 13.4 miles per hour or 6 meters per second . The initial acceleration is enormous: 500 m s−2 or 51g. For comparison, the space shuttle launches at 3g and humans pass out at accelerations approaching 10g. It takes less than a tenth of a second for the chameleon to snag its prey!
• Corkscrew Collagen: This impressive performance exceeds the capability of any muscle in biology by an order of magnitude. So what’s the secret behind the ballistics? The chameleon’s tongue has energy stored in concentric layers of a springy fiber, called collagen, wrapped around a stiff cartilage core. The powerful tongue muscle initially primes the spring by compressing it, to the same effect as a bow being pulled taut. When the tongue is launched, the spring uncoils explosively, slipping off the cartilage core. Once the sticky end snares the prey, the muscles work more slowly to reel it back in. This gives chameleons a competitive edge over lizards and other reptiles. Watch ▶ http://goo.gl/EBFty
• Breakfast at Dawn: Another advantage to this strategy is that the chameleon can catch its prey even at chilly temperatures when its muscles slow down drastically: unlike birds and mammals, reptiles are cold blooded and at the mercy of their ambient temperature. Watch how only the retraction of the tongue is slowed at low temperatures ▶ http://goo.gl/gT2hd
Slo Mo ▶ http://vimeo.com/12068409
H/T to Panah Rad for the gif ▶ http://i.imgur.com/XCytc.gif