Bat's Tongue A Showpiece Of Feeding Efficiency

Researchers at Brown University have unravelled the secrets of the fruit bat's efficiency in collecting nectar from plants. Using a high speed camera, the scientists have shown that the bat's tongue becomes engorged with blood and changes shape to become a mop-like tool the animal uses to draw nectar into its mouth.

BROWN UNIVERSITY, PROVIDENCE, RHODE ISLAND, UNITED STATES - According to researchers at Brown University, the tongue of the fruit bat (Glossophaga soricina) is one of nature's most perfectly evolved organs. When the bat prepares to feed, it's tongue becomes engorged with blood and covered with bristles to maximize its ability to collect nectar.

Using a high speed camera, the researchers, led by biology graduate student,Cally Harper, were able to record for the first time, a fruit bat's tongue changing shape to become the ideal tool for harvesting nectar from a plant. After filling with blood the bat's tongue increases in length by up to 50 percent.Under closer inspection, the researchers observed that the tiny bristles, called papillae, that line the bat's tongue also change shape during feeding. Up until now these tiny hair-like structures were thought lie dormant when the bat fed. But Cally says they actually extend, increasing the surface area of the tongue and turning it into an instrument resembling a mop. As blood is displaced to the tongue tip, the papillae flare out perpendicular to the axis of the tongue. In their erect state, they not only add exposed surface area, but also width, allowing the tongue to function as a highly effective nectar gathering device.

The researchers believe that the tongue has evolved this way to decrease the time and energy required for the bat to hover and feed.

But they also believe their bat tongue study could lead to scientific advances for humans, such as the creation of miniature surgical robots that could unclog arteries, with the same efficiency of a fruit bat sucking up its nectar.

The study was published in Proceedings of the National Academy of Sciences.