Video: Hummingbirds Are Groove-Tongued Wonders

A close-up look at feasting hummers shows how they pump nectar into their tongues.

How many licks does it take a hummingbird to sate its appetite for nectar? New research shows that thanks to their weird tongues, it’s about 15 to 20—in a single second.

It’s no secret that hummingbirds like their nectar; what’s more baffling is how these tiny birds use their long, thin tongues to guzzle up all that liquid. Since the 1800s ornithologists have believed that hummingbirds have hollow tongues that they use as straws to suck nectar up. But other scientists have noted that this method doesn’t explain how fast the birds operate. If a hummingbird needs 15 helpings of carbs in a second, it’s not going to sip at its drink—it’s going to shovel that nectar into its beak in a hurry.

To see what was actually going on, University of Connecticut research associates Alejandro Rico-Guevara and Kristiina Hurme built transparent artificial flowers filled with dyed nectar and set them up on their farm in Colombia. Then they trained high-speed cameras on the fake flowers, and filmed the 18 species of hummingbirds that visited them.  

By studying the new footage in slow motion (see the clip above, taken by Rico-Guevara), the scientists found that contrary to popular belief, hummingbirds don’t actually use their tongue to vacuum up the liquid in one steady stream. Instead, the mechanism is more like a pump. Here’s how it works: Hummingbirds do in fact have two grooves at the end of their tongues that look like hollow tubes (thus the straw idea). But as Rico-Guevara and Hurme discovered, before it goes in for a drink, the bird actually squeezes its tongue flat, compressing those hollows and building up some serious potential energy. When the tongue hits the desired liquid, the grooves spring open to their original tube-like form. They then act like pumps, loading up on nectar before being snapped back into the beak. The whole process is so quick that it only takes a fraction of a second.

Physics nerds can find a more in-depth explanation of this mechanism, including diagrams and more videos, in the researchers’ article over at The Conversation.