Sunbirds use their tongues as straws
The team took high-speed video of sunbirds drinking from transparent artificial flowers. Shown here are two views - a macro video of the sunbird drinking (top) and a close-up of its tongue inside the "flower" (bottom). The nectar in these flowers is dyed red so that it's easy to see it going into the birds' tongues. Credit: Cuban et al./Current Biology
Sunbirds may look similar to hummingbirds - small, iridescent birds with thin bills - but it turns out the two are only distantly related. Sunbirds live primarily in Africa, Asia and Australia, and have a unique way to slurp up nectar. Unlike hummingbirds, which use minute movements in their bills to sip nectar, sunbirds use their tongues as a straw. In a recent paper published in Current Biology, a team led by researchers at the University of Washington showed that these long-billed birds can change the pressure at the base of their tongues to create suction that moves nectar through their tongues and into their mouths, a novel mechanism never before seen in vertebrates. The researchers used multiple techniques - including high-speed video of sunbirds drinking red-dyed nectar from transparent artificial flowers - to demonstrate this phenomenon across multiple sunbird species as well as build a mathematical model that describes how it works. Sunbirds pollinate the flowers they drink from, and researchers are interested in understanding how different sunbird species' plant preferences affect the plant-pollinator networks across continents.
