Video clip of Enallagma civile taking off from perch.
A Web Page by Roy J. Beckemeyer
Last Updated 27 August 2001
Filmed at 1000 frames per second, played back at 5 frames per second and recorded on standard vhs, then captured as an mpv file.
Thirty seconds of clip is thus 0.15 seconds of real time. The file is 1.9MB. Watch the wings as they reach the ends of their forward or backward strokes, and you will see the trailing edge of the wing "flipping" past the leading edge. By doing so, the wing surface is given a positive camber or curvature (concave side down) that allows it to generate lift on both the fore and back strokes. Basically, the anatomically dorsal surface is the "top" of the wing on the fore stroke, and the anatomically ventral surface is the "top" on the back stroke. Also note that the fore and hind wings flap nearly 180 degrees out of phase.
© 1998 by Bill Wentz, Roy Beckemeyer, and Velvet Hutson. Camera courtesy of Crash Dynamics Laboratory, National Institute for Aviation Research, Wichita State University, Wichita, Kansas. Videography by Velvet Hutson. Project in support of Exploration Place, Wichita, KS.