Nectar-Feeding Bats Really Burn Energy--August 6, 2007

On the August 2nd episode, we talked about the amazingly high caloric needs of the cyclists competing in the Tour de France.  Now comes a study about a group of animal athletes that burn sugar three times faster than even world-class cyclists.  They’re nectar-feeding bats, and they go through their fuel faster than any other mammal on earth, according to researchers reporting in the journal Functional Ecology.  The bats hover and that kind of flight really burns energy.

The scientists fed long-tongued bats—they need the long tongues to get at the nectar in the flowers—they fed the bats sugar labeled with radioactive carbon and then measured the carbon that the bats exhaled.  They found that bats burned the sugars they ingested within minutes.  After less than a half hour they were fueling all of their metabolism with the new sugar.  The highest rates in humans are in athletes who can fuel about a third of their metabolisms from recently sucked down power drinks.  

Most mammals store energy and then access it, but the bat lifestyle required them to develop a just-in-time sugar delivery system.