Birds are some of the coolest animals because they have an ability that no other animals have…they can fly. Here's everything you need to know about bird flying.

How are birds structured for flight?

Bird flying is possible because birds have been genetically engineered to take flight. They have little bodies that are stubby and compact. This is important because a stubby body gives the bird a solid center of gravity, which helps it balance when it's in flight.

Bird flying is also possible because birds are light. Though birds have to eat a lot because they burn a lot of calories, they're structured in such a way that their weight isn't an issue. For example, birds have hollow bones. This doesn't make the bird lighter in every body part, but it helps. Hollow leg bones give the birds extra strength so they can absorb the impact of landing.

Naturally, wings are a critical component in bird flying. Wings are incredibly strong. They help the bird take off, land, steer and control their direction. Feathers on the wings rotate and help the bird move. Without wings, a bird could not fly.

How does a bird fly?

Bird flying is like airplane flying in that birds need lift to get them in the air. Gravity keeps us on the ground and in order to successfully get off the ground, we need to defy it. So does a bird. Birds create lift when they move their wings. When they create lift, they defy gravity and get air bound.

But, a bird can't just stand in place and flap its wings around and hope to fly. Bird flying lessons 101 require that the bird get some motion happening from front to back. This is where stroke comes in. Stroke creates upwards and backwards movement. A bird cerates stroke when it flaps its wings by allowing its wings to act as a propeller, cutting the air and moving it in a rotation.

All of the feathers on the bird can be rotated because they're connected and operated by the bird's muscular system. When a bird wants to be actively engaged in bird flying, it pushes its outer feathers forward. When it wants to hang out for a minute — mid-air — these feathers are held at a greater angle, which disturbs the air that's flowing over the bird's wing and slows down its flight.

Each bird's wings are made to suit the way that they engage in bird flying. For some birds, bird-flying means flying backwards whereas others need to be built in such a way that they can do more soaring.