Drinking on the Wing

Bats are exceptional multitaskers, capable of drinking water in mid-flight without crashing. 

A new study on how animals multitask details the methods the bats use to accomplish the feat.  

“Animals have very busy lives, like humans, and if they can do two tasks at the same time, they have a better chance at survival,” study author Sunghwan Jung told the New York Times. 

Most of the earth’s 1,400-odd bat species use the “skim drinking on the wing” strategy to stay hydrated, according to study author Rolf Müller. 

While everyone needs to drink water, doing so can be dangerous for animals. As a result, bats may have developed this sipping technique to stay off the ground to avoid predators, researchers say. 

To do so, bats perform in-flight drinking with various techniques. Some scoop up droplets with their tongue while flying over water, others wet their fur and then lick it, hydrating indirectly in a tactic known as “belly-dipping.” 

The study only included bats that use the first strategy and studied two Pratt’s roundleaf bats, found in Asia, and four greater horseshoe bats, typical in Europe, Africa, and Asia. Both species feed on insects. 

Researchers left the bats without water for six hours and then, in a lab large enough for them to fly around, they inserted a water source. They set up multiple cameras near the water and used stereoscopic imaging to check specific parts of the bats’ bodies as they dived down to drink. They then combined the imagining to get a 3-D viewing of how the bats flew around and sipped the water. 

They found that bats slowed down while approaching the water, similar to what humans do while multitasking. Researchers think this motion of slowing down might be due to the challenge of multitasking, but also to the difficulty of flying so close to the water’s surface. 

To avoid their wings touching the water, the bats reduced the range of their strokes by about 50 percent. They also adjusted their flapping motion to a steeper angle to compensate for the drag created by the tilt of their heads. Bats also meticulously controlled their tongues while scooping up the water. Researchers explained this is done to avoid getting water in the nose as this organ is fundamental to bats’ navigation system. 

Watch a bat get an in-flight beverage here.