The longest tongue (relative to body length) ever reported in a mammal resides largely inside the ribcage of a recently discovered bat in the mountains of Ecuador. The tongue of the tube-lipped nectar bat (Anoura fistulata) is one and a half times as long as its body.
Nathan Muchhala of the University of Miami (Florida) discovered the new species with the support of a BCI Graduate Student Research Scholarship. He concludes that this remarkable bat evolved in tandem with an extremely long, trumpet-shaped flower, which averages about 3 to 3 1/2 inches long. That turns out to be roughly the length of the tube-lipped nectar bat’s remarkable tongue.
In a spectacular example of co-evolution, as the flower became longer over millennia, the bat’s tongue apparently elongated to reach the nectar stored at the base of the ring of petals. “It is,” Muchhala says, “like a cat being able to lap milk from two feet away.”
In return for the nectar, the bat pollinates the flowers – and it apparently is the only species that can do so.
Managing such an extraordinary tongue requires unusual morphology, Muchhala said. In other nectar bats and most mammals, the base of the tongue is attached to the base of the oral cavity, and the tongue is stored in the mouth. In the tube-lipped nectar bat, however, the tongue continues down through the neck and ends up between the heart and sternum.
Measuring bats’ tongues was a challenge. Muchhala trained captive bats to drink sugared water from a modified straw. Two other nectar-eating species – the Geoffroy’s long-nosed and tailed tailless bats – were able to reach the water down to about 1.5 inches. The tube-lipped nectar bat was still drinking at 3.3 inches.
BCI members can read the complete story of Muchhala’s research in the winter issue of BATS magazine.
BCI’s Student Research Scholarships support students conducting conservation-relevant research around the world. You can help. Please contact the BCI Department of Development at firstname.lastname@example.org.