What bat has the longest tongue relative to its body size, used for feeding on nectar?

The bat with the longest tongue relative to its body size, used mainly for nectar feeding, is the tube-lipped nectar bat.

The tube-lipped nectar bat, Anoura fistulata, is a small bat from the Ecuadorian Andes. Its tongue reaches about 8.5 centimeters—roughly 150 percent of its body length—and much of the extended tongue is stored inside the rib cage when not in use.

This remarkable structure lets the bat reach nectar deep inside long, tubular flowers. One important example is Centropogon nigricans, whose long corollas are pollinated exclusively by this bat. The relationship is a striking example of specialized coevolution between a flower and its pollinator.

Despite its name and spectacular tongue, the bat is not limited to nectar. It also eats pollen and insects. The “tube-lipped” name refers to its lower lip, which extends beyond the upper lip and curls into a funnel-like shape. The species was first described in 2005, and its scientific name fistulata comes from the Latin word fistula, meaning “tube.”