New physics model explains why birds flap wings during landing
Research suggests wing-flapping helps birds maintain control and stop within short distances, according to a study published in Proceedings of the Royal Society A.
New physics research suggests that birds flap their wings during landing to solve aerodynamic challenges rather than wasting energy, according to a Times of India report. The study, published in Proceedings of the Royal Society A, indicates that flapping provides the necessary control for a safe touchdown.
Researchers Tom Rottier and Ben Parslew from the University of Manchester, along with Philippe Lavoie of the University of Toronto, used mathematical modelling to test unpowered landings. They found that while a zero-speed landing without flapping is theoretically possible, it is impractical for most birds.
For a bird the size of a pigeon, the model showed that stopping without flapping would require an initial speed more than twice its usual cruising speed. Such a landing would also require approximately 60 metres of horizontal travel and a climb of roughly 20 metres.
Dr Ben Parslew stated that landing involves more than just slowing down, as a bird must decrease speed while keeping enough aerodynamic control to finish the move safely. Flapping allows birds to adjust their path late in the approach and avoid stalling.
The model also explains why birds of prey, such as Harris’s hawks, swoop below a perch before rising to land. The researchers found that touchdown speed influences this behaviour, helping birds manage their arrival speed and limit time spent in a less controllable state.
The findings may eventually assist in the design of drones and aerial vehicles that need to land in tight spaces. The study suggests that the need to be light for flight but strong for landing may have influenced bird evolution.