The surprising secrets of hummingbird flight - Kristiina J. Hurme & Alejandro Rico-Guevara
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Hummingbirds are legendary for their relationship with flowers, and the tremendous amount of energy they obtain from nectar each day. Did you know that if a hummingbird consumed nothing but nectar, it would actually get very sick and weak, and ultimately wouldn’t survive? This is because a hummingbird requires other nutrients as well, particularly protein. That’s where their other source of food comes in: small insects and spiders. Hummingbirds will glean these tiny protein bundles from bark and leaves, or simply in midair—a technique known as hawking. In fact, scientists studying one hummingbird found that she ate nothing but arthropods for two weeks!
Of course, insects are fast. So how do hummingbirds manage to catch them? It turns out that hummingbirds can snap their bills closed in less than a hundredth of a second, using a technique known as snap-buckling—actually bending their lower beaks down, which then spring up faster than you can blink! Check out this link to see a photo of what these flexible beaks looks like in action.
Wicking theory debunked
Until very recently, hummingbirds were thought to lap up nectar using something called capillary action, or wicking: when a liquid travels against gravity, up through narrow spaces, due to forces of attraction between molecules of the liquid and the tube’s very surface. Only just five years ago, scientists showed that the hummingbird tongue, forking into two fringed and skinny grooves, instead operates like a micro-pump! These grooves, flattened while inside the bill, will gradually relax into their cylindrical shapes as they dip into and subsequently fill with nectar—which is then squeezed out of the grooves when the tongue enters and exits the beak once more, and the process starts all over again. It turns out that this method is faster than wicking, letting a hummingbird lick a flower about 20 times a second. This amazing video shows hummingbird tongues up close and personal—when it comes to hummingbirds, the tiniest details can be some of the most important, and the difference between going hungry or not!
Floating in midair
Hummingbirds are elegant, graceful acrobats in the air, and remarkably precise thanks to their abilities to hover and beat their wings so quickly. Their figure 8 wingbeat pattern is actually more like that of insects than other birds, and this lets them produce between one-fourth and one-third of their lift simply on the upstroke of each flap (the process of the wing returning to its highest position, in order to flap downwards again). Most birds, on the other hand, can only lift themselves up when flapping downwards. This special flight pattern is made possible by the tireless work of a hummingbird’s enlarged pectoralis and supracoracoideus muscles, in combination with their wings rotating like miniature propellers at their humerus (shoulder) bones.
Incredibly, we can’t see most of this activity without the help of high-speed cameras. Watch this video to see a hummingbird in ultraslow motion, at a speed that our human eyes can appreciate!
We could list astonishing statistics about hummingbirds all day, but here are some simple hummingbird-to-human equivalencies, to put things in perspective:
- If a human were to expend as much energy as a hovering hummingbird, they would need to drink about one can of Coca-Cola per minute!
- To consume a proportional amount of energy to a hummingbird in one full day, a human would have to eat roughly 300 hamburgers.
- Hummingbird forward flight speeds (not diving, which is faster) have been recorded at roughly 30 mph. Usain Bolt, for comparison, made his world record at 27.8 mph!
- When diving, hummingbirds can reach G-forces equal to those experienced by fighter jet pilots—but pull up at speeds that would make those pilots black out!
- Here’s one you can try out yourself: blinking is one of the fastest movements human muscles can perform. A particularly speedy blink lasts maybe 100 milliseconds—that would equal an absolute maximum of 10 blinks in a second. Some hummingbirds, meanwhile, can flap their wings up to 80 times per second (roughly 12.5 milliseconds per flap)!
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