Owls may be one of the best silent attackers in the wild as a new study found that the species are capable of using "stealth technology" to hide their wing noise while attacking preys.
The feathers of owls can take in aerodynamic sound and inhibit the vibrations that develop when the nocturnal creatures flap their wings. The new study aim to analyze the desensitizing capacity of the owl's primary flight feathers on their wings or remex.
The researchers from the Dalian University of Technology in China conducted the research by utilizing high-speed cameras and observe the feathers of three bird species including the eagle, pigeon and the long-eared owl while flying. The three birds have dissimilar sizes; however, the manner with which they beat their wings are fairly the same. The researchers also used a laser displacement sensor to note the differences in the amplitude of the measurement points on the axis with wind-calculating structures.
The findings of the study, published in the Institution of Civil Engineers Virtual Library, show that the feathers and barbs of the long-eared owls sustained higher loss factors in the amplitude-time investigations compared to those of the pigeon and golden eagle. This means that the extent of vibration exhibited by the long-eared owls disintegrates more rapidly and thus, present higher vibration-impairing features. The resulting action of this characteristic is the ample suppression of mechanical noises created by the owl's primary feathers when beating its wings.
This particular behavior of owls has captured the interest of many engineers, as the research aim to find applications of their study findings to various industries and situations for the benefit of the communities, says Professor Jinkui Chu, the study's lead author. After the study, the researchers discovered that the ability of owls to fly so quietly is much more remarkable than they initially thought of. More than inhibiting aerodynamic noise as they glide, the owls are also able to suppress mechanical noise as a result of vibration during flight. With this, it can be said that owls are the kings of acoustic stealth, Chu comments.
Through this study, the researchers hope to help in the field of engineering to develop structures and inventions that can help to eliminate noise as they function.
Photo: Peter Trimming | Flickr