Owls are famously known for their cunning hunting skills – and a new study has shown owls are equipped with highly developed stealth technology which allows them to approach prey undetected.
When any bird beats its wings there is sound and vibration, but an owls feathers absorb aerodynamic sounds and vibrations by converting mechanical energy into heat – the result is absolute silence when on the hunt.
High-speed cameras and lasers were used to compare different species of birds’ feathers during flight, and although the birds used in the case study differed in size, they all had similar wingbeat/flapping styles.
Lead researcher professor Jinkui Chu of Dalian University of Technology in China had this to say:
“Many owls have a unique and fascinating ability to fly so silently so that they are out of their prey’s hearing range, due to their feather structure.
“This behaviour has long been of interest to engineers, as we seek to apply the owl’s noise-reduction mechanisms to other purposes and situations that benefit society.
“Now, however, we know the owls’ silent flight ability is even more superior than we thought. You could say of all birds it is the king of acoustic stealth. It not only manages to suppress aerodynamic noise when gliding, but also mechanical noise caused by vibration during flying.
“This is remarkable, considering the sudden jumping, bending and twisting the wings are subjected to when flapping and the noise that it creates for other birds.
“In the scientific world, the process used to eliminate this mechanical noise is called ‘damping’, which means the extraction of mechanical energy from a vibrating system usually by converting it into heat and allowing it to remain steady.
“Our research showed the long-eared owl has superior damping skill, meaning it can remain mind-blowingly stable and eliminate mechanical noise caused by the movement of its feathers - quite a feat of engineering.”
“This study will hopefully provide further insight into the owls’ silent flight mechanism and help engineers develop ideas for special materials or structures, such as on-shore wind turbines, where similar noise elimination can be applied.”
You can read more about this in the Institution of Civil Engineers’ journal Bioinspired, Biomimetic and Nanobiomaterials.
Bird technology is pretty high tech, don’t you think?