Just like the motion of sculling a skiff through the water, the motions involved in natural flight are never a symmetrical straight-up-and-down wing movement. Instead, it's a looping motion which rotates the direction of the lift force to provide forward thrust and increase speed -- as opposed to gliding, which is a more passive form of flight.
Wing shape, of course, plays a role in the patterns involved in flapping -- but the similarities between these patterns are equally as fascinating. The flap of a dragonfly's hind wing bears some similarities to the flap of the wing of a bat -- and a hummingbird and a moth have something in common to.
We know this because of the work of Seattle-based designer Eleanor Lutz, who has a degree in molecular biology from the University of Washington. Lutz's project is a blog, for which she creates beautiful infographics about biology, using Photoshop, Illustrator and a Wacom drawing tablet.
In the infographic below, she has deconstructed the wing patterns of five flying species: an Egyptian fruit bat, a Canada goose, a dragonfly, a hawk moth and a hummingbird. To get an accurate map of each flight, she carefully traced frames from slow-motion videos of these animals in flight.
"When I worked in an insect lab as an undergrad, I helped out with an experiment about mosquito larvae. As part of the process we used a Matlab program to manually input the larva's location during thousands of video frames," she wrote.
"It was a fun experiment, and I wanted to make something similar from YouTube videos. I found slow-motion videos of five flying species, and mapped out specific points on the wings during one wing beat. I ended up with 15 frames per wing beat, and I connected every frame using imaginary curves that went through all of the 15 mapped points."
Lutz notes that 15 frames isn't enough for any kind of rigorous analysis or conclusion, and that the infographic is more for the purposes of art and fun, but that her next post will be more scientific. Meanwhile, she has made a poster version of the work available for purchase via Artsider. You can also check out more of her work on her blog, Tabletop Whale.