Human have been staring at birds with jealousy for centuries. These magnificent creatures are soaring high in the sky like nobody’s business and we would like to be so fabulous as well. But not all birds have the same abilities. Some can do tremendous acrobatic tricks, some can even hover, while others are very good at gliding. A research from the University of British Columbia explains how nature prepares wings for different flight.
Some birds have similar abilities. For example, hummingbirds, falcons, hawks, kingfishers and passerines can hover, but their wings are very different. At the same time ravens are great high-flyers, while crows, which have very similar wings, prefer staying lower to the ground. How come?
Scientists from UBC decided to figure that out. They categorized 61 species of birds by flight style (from hovering to gliding to soaring). Then they analysed samples of wings, collected through the years and matched them to the way these birds fly. They also took evolutionary tree into account, to see at which point in natural history did these birds evolve a particular way of flying. This research lead scientists to an interesting conclusion – when birds learn a new way to fly, they do not reshape their wings. Instead, they reshape the range of motion of their wings.
Scientists measure shape, flexibility and extendibility of birds’ wings
Vikram Baliga, lead author of the study, said: “Birds essentially swim through the air—they flex, extend and bend their wings in flight. As a bird specializes in a flight style, nature doesn’t appear to reshape the size or shape of the wing as much as it remodels the wing’s range of motion. Much like a swimmer adjusting their stroke”.
For example, hovering birds have limited ability to extend their elbow joints, but have very flexible wrists. Elbow joints are more developed in those birds that can glide for long distances. In other words, the tools are different, but different birds may be using them in the same way.
Interestingly, scientists are not looking at this subject as only a matter of biological interest – they are convinced this knowledge could help developing our own technology. While nature tested many wing designs in the course of evolution and used them in different ways, some wings are highly efficient. Understanding their mechanics and how wings in nature morph during flight could help us improving unmanned aerial vehicles. This could help creating wing designs that are better at withstanding turbulence, wind gusts, or even aerial predator attacks.
Do you want to know something weird? We can send robots to Mars, we can create self-driving cars, we can build robots that help rescuing people, but it is still tremendously difficult to build a drone that mimics bird’s flight perfectly. It is that complex.
Source: University of British Columbia