It’s no secret that the aerospace industry has always taken hints from nature, for designs of new aircraft. As amazing as our modern engineering and material sciences are, it still can’t hold a candle to millions of years of wild evolution. One can only wish to fly as good as a Peregrine Falcon.
Sharks however are not creatures that comes to mind when thinking about the physics of flight. But, the iconic head of the Hammerhead Shark seems to serve the same purpose as the wing of an airplane. At least, that’s the leading theory about why they evolved such a bizarre head.
Lift or maneuverability?
The increased drag of its giant head means the Hammerhead has to work much harder and use more energy to swim, compared to other streamlined sharks and dolphins. They don’t have a swim bladder either, so they HAVE to keep swimming to avoid sinking. So it made sense to believe that the giant head acted as a wing, to help the Hammerhead stay vertically positioned in the water column. Same as a plane’s wing provides lift in the air.
It makes sense. The name of the shark’s hammerhead, called a cephalofoil, even means “head-wing”. But, in studies, the flow of water over the head does not behave like air over a wing. No more lift is created by the head, when compared to other sharks. So if the head ISN’T a wing to provide lift, what’s it for?
Survival of the fittest
When the shark’s angle of attack changes (AOA), is where the answer lies. The hammer is not for lift, it’s for maneuverability, and it makes them more maneuverable than any other shark in existence. That means they can tap an ecological niche of food that other sharks can’t get, like prey who dwell on the sea floor.
Such creatures make erratic escape attempts when chased by a threat, darting in all directions at the blink of an eye. The unique wing-shape of a Hammerhead’s head means they can maneuver fast enough to catch those food sources.
We thought it was interesting. Nature always knows best.
