A new study has shown that how hummingbirds feed has been misunderstood for more than 180 years. Instead of sucking in nectar from flowers through their tongues like straws—a hypothesis that was yet to be proven wrong by the scientific community until recently—new research suggests that hummingbird tongues work more like tiny pumps instead. You can watch the high speed footage of feeding hummingbirds from the new study here!
Strange Tongues
The key to the hummingbird’s survival is all about intense speed and constant motion, never able to stay in one spot for too long. Because of this, it would make sense that their tongues would be equipped with features that let them feed in a hurry, shifting from flower to flower at blinding speed.
Hummingbird tongues aren’t as fleshy as those found in mammals, and they don’t have as many muscles spread throughout. Instead, they are extremely thin, tube-like tongues that can pierce right into the nectar-filled hearts of flowers, and are forked at the end—each prong is tube shaped in order to allow hummers to suck up nectar.
A Centuries-Old Misunderstanding
Previously, scientists thought these tongues used capillary action to suck in fluid from flowers, soaking up the nectar with porous tongues, using the same method that sponges and paper towels do to soak up liquid. However, computer testing has never been able to show how hummingbirds use capillary action in the blindingly fast speed that they use when feeding—able to feed from a flower as many as 20 times per second–as it is a generally slow process.
Alejandro Rico Guevera, lead researcher of the new study at the University of Connecticut , knew something wasn’t quite right with this old hypothesis. Recording dozens of different types of hummingbirds using state of the art slow-motion cameras, Guevera was able to determine exactly how hummingbirds truly feed. Instead of using the more passive and slow process of capillary action, the new footage shows evidence of their tongues being tiny elastic micropumps instead.
Tongues Like Micropumps
New footage (which you can watch here) shows that when a hummingbird flicks its tongue out towards the center of a flower, the tip of its tongue is squeezed shut. Upon making contact with the nectar, the tip opens up, in effect “pumping” fluid up through the two prongues, and into the hummingbird’s cylindrical tongue. The hummingbird then draws the tongue back into its mouth, squeezing the nectar out with its beak. This process flattens the tongue, so that when the hummingbird’s tongue shoots out again to collect nectar, it will be flat again, ready to re-open and pump out nectar.
The hummingbird is able to repeat this process upwards of 20 times per-second, which is consistent with the numbers crunched using computer models. In 2011, scientists discovered that the hummingbird’s tongue could not be a capillary tube, as the capillary action process would be too slow, but they could not figure out just how hummingbirds were able to feed instead.
Published today in journal proceedings of the Royal Society B: Biologicalb Sciences.
For our birders out there!
Another quick bird-related piece.
