Written By: Sarah Girton
“A blog series about birds, and you haven’t even talked about flying yet?!”
I know, right?
Without question, the most amazing thing about birds is their ability to seemingly defy gravity and take to the skies. Whether they take off right from the ground, or need a running start, they make it look so easy. But in fact, a combination of highly-tuned adaptations make bird flight possible.
As I mentioned in the introductory post of this series, the first known flying bird-like creature was Archaeopteryx. But this guy looked a little bit different than modern birds. He had teeth instead of a beak, and a long, bony tail. Since then, birds have become better-suited for flying. They developed a beak, which is lighter in weight than a mouth full of teeth. They also lost the bony tail, and their skeletons lost extra weight by developing air cavities inside their bones .
The science behind bird flight is quite fascinating, and even more complicated than some might realize. Let’s start with an overview of bird morphology. A bird’s wing is a curved surface from front to back, allowing lift, while reducing drag. The pectoralis major, the breast muscle, is a bird’s strongest muscle, allowing for as little exertion as possible with each beat of their wings.
There are three main types of bird flight: Gliding, flapping, and bounding. With gliding, birds use upward air currents called thermals. Many species of seabirds use this method since it requires the least amount of physical exertion, as many of them only return to land in order to breed and raise young. Flapping flight is a steady motion of flapping wings in order to stay level. This type of flight provides a constant lift while also causing a forward thrust. And bounding flight is used by a lot of smaller birds. With a short, sporadic burst of wing beats, a bird can gain some serious forward motion and then fold its wings against its body to shoot forward like a little torpedo.
The Effects of Bird Flight on Human Culture:
For all of human history we have been captivated by flight, longing to harness this superpower for ourselves. Myths and stories of flight populate world cultures, like the Greek story of Icarus, who flew on wings of feathers and wax, only to fly too close to the sun. And it seems silly not to throw in an obligatory Superman reference!
But unlike mythological and fictitious characters, we had to study and research for centuries, if not millennia, before we could do it. According to author Tom Crouch in his book Wings: A History of Aviation from Kites to the Space Age, one of the first recorded attempts at human flight originate from Ancient China, where they utilized man-carrying kites, which were sometimes used as a punishment for prisoners.
One of my personal favorite forms of human flight is the hot air balloon, which saw extensive development in France around the end of the 18th century by the Robert brothers, Anne-Jean and Nicolas-Louis. They famously flew their hydrogen balloon from the (now destroyed) Tuileries Palace in Paris to Nesles-la-Vallée after about two hours.
Various companies and private individuals have even invented personal flight systems. Maybe one day these will catch on, and there will be a sky full of rocket-strapped humans?
In all the ways that birds inspire and delight us, flying has got to be near the top of the list! Who doesn’t feel a sense of freedom and joy at watching a bird break the bonds of the earth and soar, free to go anywhere at any time? And the funny thing is…birds sure seem smug about it…(that’s my lame segue into next week’s topic: Bird humor!)