A story of Lilliputian lizards and their turbo tongues
New research shows that the tongue of itty-bitty chameleon, Rhampholeon spinosus, displays the highest acceleration of any reptile, bird, or mammal!
It comes as little surprise that chameleons have lightning fast tongues … they stalk, they strike, and wham! But a new study by Brown University biologist Christopher Anderson reveals that we didn’t really even know the half of it. Traditionally larger species of chameleons have been studied, but when Anderson trained his focus on the littler guys, fascinating new powers were revealed.
Looking at 20 species of chameleons from massive to minute (and for the record, the chameleon pictured above is just a random cutie and not associated with the study), Anderson found that across all of his measurements there was a correlation between size and tongue speed. In fact, the smaller the lizard, the higher the peak acceleration, relative power, and distance of tongue extension were relative to body size.
"Smaller species have higher performance than larger species," said Anderson, a postdoctoral research associate in the Department of Ecology and Evolutionary Biology.
What’s their secret? In general, chameleons don’t exclusively rely on spontaneous muscle power to whip out their tongues. Most of the motion's total energy is preloaded into the tongue’s elastic tissues. The recoil combined with muscle spells curtains for nearby bugs.
Of the 20 species Anderson measured, the perky Rosette-nosed Chameleon (Rhampholeon spinosus) took the cake (or the cricket as the case may be). The ballistic tongue projection of this 4.8 centimeter lizard (less than two inches) produced a peak acceleration 264 times greater than the acceleration due to gravity. If its tongue were a car, it could go from 0 to 60 miles per hour in a hundredth of a second.
© The total power output of Rhampholeon spinosus' tongue was 14,040 watts per kilogram. (Image: Christopher Anderson)
Anderson's research suggests that the motion has the “highest acceleration and power output produced per kilogram of muscle mass by any reptile, bird, or mammal and is the second most powerful among any kind of vertebrate” … only a salamander outdoes it.
While all chameleons have the same mechanics for launching their lightning tongues, the smaller guys likely need more power since they need to consume more energy per body weight to survive, explains Anderson. They’ve evolved to have exceptional hunting techniques in order to successfully compete for all of the nutrition they require.
The moral of the story? Don’t underestimate the little guys.
"What this study shows is that by using smaller species, we may be able to elucidate these higher performance values," says Anderson.
In this short video watch a super slow-motion clip of a von Höhnel's chameleon (Trioceros hoehnelii) showing off its oral prowess: