In stories old and new alike, real and imagined, people dream of taking flight. Though this illusion has metaphoric symbolism, the act of flying nonetheless intrigues humans. An act which birds accomplish not with the assistance of technology but through their very form. By examining the mechanisms and traits that enable a ‘birds eye view’, perhaps we can begin to understand why flying is sensational in lieu of the sensation of flying . . .
To begin, birds possess specialized bones, which facilitate flight. These bones are pneumatic or air-filled, a trait which was also common in some dinosaur species including the iconic Velociraptor and T. rex. [1] Lightweight bones allow for lift off. In addition, avian skeletons have fewer bones overall either through evolutionary loss or fusion [2]. Bone fusion transfers shock and stiffens the body of birds in flight thereby stabilizing them. Powerful muscles are also important for flying, especially for flapping flight. Unlike gliding, flapping flight requires constant up and down movement of wings accomplished by large pectoralis and supracoracoideus muscles.
Of course, wings are also necessary for flying, but how do they work? Can this tool be recreated? In the sense of re-imagining and not duplicating, man-made ‘wings’ have already been invented and function in a similar fashion to bird wings. For each incarnation, bird or airplane, air moves above and below wings at different speed creating force at different angles. High pressure builds under the wing as opposed to over the wing creating lift. Similarly, thrust and drag are terms used to describe horizontal momentum and delay. Birds and pilots can adjust the angle of their wings relative to surrounding air to change directions.
Though wonderfully beautiful in their variety, feathers do serve a functional purpose in relation to flying. The closing and separation of feathers allows less or more space for air to penetrate. For this reason, birds can incrementally change flight patterns between take off, gliding, flapping flight, and soaring*. Additionally, birds use wing and tail feathers to control speed and direction.[3] Please visit the Canadian Museum of Nature to watch and learn about different stages of flight.
Rather than removing the mystery, understanding the intricacies of flight only strengthens our sense of wonder. As individuals or amassed, poetry in motion.
*Only some birds have mastered soaring.
Further resources:
- YouTube Video – “How Do Birds Fly?”
- Podcast – Evolution of Bird Flight
- Blog entry – Falcon vs. Raven in Slow Motion
- Gallery of birds (and other animals) in flight from Flightartists Project
[1] http://www.ucmp.berkeley.edu/science/profiles/wedel_0609.php
[2] http://www.hsu.edu/pictures.aspx?id=1287
[3] http://wiki.answers.com/Q/How_do_birds_fly
Our eNews features information on exhibitions,
upcoming events, and subscriber-only special offers!
Sign Up for eNews