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Similar to surfers, pelicans have figured out how to harness energy from waves. However, it is actually more closely related to what a pilot does during take off and landing than to surfing. Interestingly, it appears pelicans are one of only a few coastal birds to have figure this out. By flying so close to the rolling wave, they are able to gain lift, speed and decreased wind resistance created by the air that gets trapped between the water surface and the underside of the wing. This air cushion essentially supports the bird’s weight just above the water’s surface. As the wave increases in height the pelican rises up parallel to the wave to maintain lift. Just prior to the wave breaking, the bird will then descend along the leading edge of the wave, gaining speed along the way much like a surfer does. By doing this they can greatly increase their flight speed without ever having to flap their wings. The key for the pelican is to build up as much speed as possible before the wave breaks. Just as the wave starts to crash over itself the pelican resumes flying to get above the resulting air turbulence. As the next incoming wave moves into shore they reposition themselves along its leading edge and repeat the maneuver. In this way they can travel much longer distances much more quickly and with less effort than other birds. While pelicans and albatross were showing us how to use this effect well before we recognized its existence, it wasn’t until the Wright brothers came along that anyone used it. Even then, no one knew what it really was. Now the phenomenon is well described and in the aviation world it’s known as ground effect. Anyone that has flown in an airplane has felt this either at take off or landing. In large planes it is most noticeable just before landing, when the plane seems to hover just above the ground and actually gain speed just prior to touchdown. In small planes it is more noticeable at take-off, when the pilot maintains the airplane just off the ground to help increase the ground speed before ascent. Next time you fly watch for this effect and you will surely notice it if you haven’t already.
Owen Slater Photography 