Tiny Chameleons Have the Most Powerful Tongues
When a chameleon sticks out its tongue, the organ acts more like a bullet than a muscle. The lizard can ballistically project its tongue up to twice its body length, at speeds much faster than what's possible with the muscle contractions other species use. However, tongue power is not equal among chameleon species. Smaller chameleons’ tongues have some of the fastest accelerations and greatest power outputs of any animal movements around, according to a new study in Scientific Reports.
The study, by Brown University’s Christopher Anderson, documented the feeding behaviors of 20 chameleon species. Watching through a high-speed camera as 55 different chameleons nabbed their prey 279 times, he found that smaller chameleons could throw their tongues as far as 2.5 times their body length. The tiny Rhampholeon spinosus chameleon’s tongue accelerated at a rate 264 times greater than the acceleration an object experiences from gravity at sea level. That’s the equivalent of a car going 0 to 60 miles per hour in one-hundredth of a second. By contrast, the tongue of a two-foot-long chameleon experienced 18 percent less acceleration.
The power and acceleration necessary to create that kind of movement is, proportionally, one of the greatest outputs seen in any vertebrate. The R. spinosus chameleon, an endangered chameleon only a few inches long, used a power output of 14,040 watts per kilogram (an ability second only to a salamander).
The smaller the chameleon, the higher the peak acceleration, relative power, and extension distance its tongue was capable of, Anderson found.
Because many studies of chameleons have focused on larger species, which have proportionally smaller tongues than their more miniature relatives, the animals' abilities have probably been underestimated in the past. This study shows that to truly figure out what these creatures can do, you’d better look to the little guys.