Activity › Discussion › Science & Technology › Why Birds fly? › Reply To: Why Birds fly?
tanyaMemberMay 8, 2021 at 1:33 pm::
Before understanding the reason behind birds flying in the air, we have to understand the concept of Aerodynamics. It is the scientific study of the way that things move through the air. Anything that moves through air is an application of Aerodynamics, be it an airplane or a kite or even a bike that moves on-road, as it cuts the air as well, so it is also an application of Aerodynamics. There are four forces of Aerodynamics- Lift, weight, drag, and thrust.
Weight is the force that pulls anything towards Earth because of gravity. Lift is the force that acts opposite to that of weight. If this force is more than that of the weight, it helps the object to move upwards. Weight and lift are vertical forces, whereas drag and thrust are horizontal forces. Drag is the force that tries to slow down the object. It makes an object hard to move. On the other hand, thrust is the force that acts opposite to drag. It is the push that moves something forward. For an object to move in the forward direction, it should have more thrust than drag. Now coming back to the question of birds. Why and how do they fly? Birds are lightweight and have smooth feathers, which makes the forces of weight and drag almost negligible. In addition to that, they also have just a beak instead of heavy jaws and teeth, which also makes the value of weight significantly less. They also have a streamlined body which weakens the force of drag. Birds use their legs to push off the ground into the air. And then they use their flaps to stay in the air.
The wings of birds also play a substantial role in their flight. Their wings are curved that keeps the air above and below the wings and helps the bird fly in the air. The increased speed creates a longer path of air, which then explains the air moving quickly over the wing’s top surface, reduces air pressure on top of the wing, and therefore creates lift. The larger the wings, the more the lift generated by them. Light bones, strong legs, larger wings- all these are the characteristics required by birds to fly. Birds also fly so that they don’t get hunted by the animals that are too eager to eat them. Apart from that, there is one more reason why birds fly. Just like we get bored sitting at one place, birds also tend to get bored staying at one place. They don’t much like the cold weather or sometimes vice-versa. So, they tend to fly from a cold atmosphere to a warm environment. This phenomenon is also called migration. Once the birds are out in the air, they don’t need to flap their wings again and again to fly. Once they are up in that sky, they can glide, which can also be explained as a free ride that they gift themselves. They only need to flap their wings once in a while. Also, they can let a jet of air push them up even higher; in that case, they need to balance themselves properly.