Video: Bat’s tongue baffles researchers

Most nectar-feeding animals evolve special quirks (mainly of the tongue) that optimize their eating habits. But for the groove-tongued bat Lonchophylla robusta, evolution has dealt a bit of a strange hand. Instead of lapping up or siphoning liquid as other mammals do, this bat hovers over its food source and dips its long, slender tongue into the nectar, keeping contact the entire time it drinks. Researchers filmed the bat with a high-speed video camera to try to decipher the special tongue mechanism, and watched as the fluid flowed upward along the bat’s tongue, against gravity, and into its mouth. Today, researchers report in Science Advances that the conveyor belt–like mechanism may actually allow these bats to feed more efficiently from certain types of flowers. Exactly how the nectar travels up the tongue is still a mystery, but they suspect that the transport likely comes from a combination of grooves in the tongue and capillary action—a fluid action that allows liquid to flow through narrow channels (the same mechanism that lets paper towels soak up water). So far, the groove-tongued bat is alone in its anomalous nectar slurping technique, but the finding opens up new areas in fluid dynamics and ecology for researchers to explore.