Hummingbirds are without a doubt one of the more mind-blowing feats of evolution. These feathered little freaks can fly in extraordinary ways -- almost like a hybrid between bird and insect thanks to their speed, agility and small stature. Indeed, there is even a species called the Bee Hummingbird that is merely 5 centimeters long and earns the title of world's smallest bird.
So how do hummingbirds do it? How can they fly so fast? How can they hover in mid-air and move with such precision? And how do they manage to even fly backwards? These are questions that researchers have spent years trying to figure out.
Tyson Hedrick, a biologist at the University of North Carolina in Chapel Hill, led a study recently, the results of which were published in Nature. The team used wind tunnels and high-speed cameras to find out exactly how hummingbirds move. Turns out, the secret is all in the wrist.
Hummingbirds invert their wrists to move their wing in an entirely different way than other birds. "In most birds, the wrist collapses on the upstroke to draw the wing towards the body as it is raised. Hummingbirds have adapted the same movements to rotate their wings instead."
“It has adopted an insect-like flight style with the evolutionary heritage of a vertebrate,” says Hedrick. “It has got essentially the same arm bones that we have but it’s doing this funny thing with its shoulder, flipping the wing back and forth like a fruit fly rather than a pigeon.”
See... check it out:
This kind of movement is what allows them to fly forward, backward, up, down, and even sideways. And with speed! The average flight speed for a hummingbird is 25-30 mph. Some can dive at speeds reaching 60 mph. It all comes with the speed at which they can flap their wings. The a medium-sized hummingbird can beat its wings 20-30 times per second, or between 1200-1800 times a minute!
As Nature puts it, "Small animals have to beat their wings faster than larger ones to stay aloft, and they risk losing muscle power in the process. Hummingbirds and insects have converged on the same solution: by using their muscles efficiently, they can produce a large amount of power with fast but small movements."
"It may not be the elegant, symmetrical flight of insects, but it works," said Douglas Warrick, an assistant professor of zoology at OSU, when studying how these birds manage to hover. "It's good enough. Hovering is expensive, more metabolically expensive than any other type of flight, but as insects have found, nectar from a flower is an even bigger payoff."
Here's a great show from PBS called Hummingbirds: Magic in the Air that goes into detail about these wonderful little birds.