Tuesday, August 25, 2015

Hummingbird Tongue II

Blue-Tailed Hummingbird - Honduras - Courtesy Robert Gallardo
Back in May in Hummingbird Tongue we discussed the new findings of how a hummingbird's tongue worked based on new postmortem studies.  To quote from that report:
"The hummingbird has a forked tongue which is lined with hair-like extensions called lamellae. When inside the flower, the tongue separates and the lamellae extend outward. As the bird pulls its tongue in, the tips come together and the lamellae roll inward. This action traps the nectar within the tongue."
New studies have expanded our knowledge of the physics involved in fueling a hummer, functioning as a tiny elastic pump. Using tiny glass tubes with artificial nectar, researchers made high speed videos of 18 species of hummingbirds in Connecticut, Texas, California, Ecuador, Columbia and Brazil.
"We show that the tongue works as an elastic micropump," the researchers said. "Fluid at the tip is driven into the tongue's grooves by forces resulting from re-expansion of a collapsed section" of the tongue closer to the mouth.  This fast technique allows the bird to drain between five and 10 drops of nectar from a flower within 15 milliseconds (about 100th of a second)," Rico-Guevara told Livescience.com
The part of the mouth closest to the beak expands, drawing in fluid which is then pumped into the throat.  Even more incredible, it involves the tongue structure alone, not involving any muscles or nerves.  Studies like this only make me wonder what we will learn about the physics of bugs that can suck the juice out of a stiff plant stem, or more personally, a mosquito blood out of my skin.

Photograph above is from our friend Robert Gallardo who has written Birds of Honduras.  He guides birders through Honduras which is the winter home of 60 of our Missouri migratory birds, especially warblers.  More information at Birds of Honduras.

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