Birds have several adaptations, such as an aerodynamic and streamlined shape, feathers on their wings and body, and the physical forces of lift, drag, weight, and thrust, which enable them to fly. Lift is achieved by flapping their wings, which causes air to move faster over the upper surface of their wings and body, reducing surrounding air pressure and lifting them higher into the sky. Drag is resistance caused by air pushing against the bird, slowing down their flight speed. Weight is countered by the bird’s hollow bones and lightweight feathers, enabling them to move higher into the air against gravity. Thrust is achieved by flapping their wings to create forward motion needed to take off and be propelled through the air.
Feathers play a crucial role in supporting birds in every aspect of flight, from becoming and remaining airborne to balancing, controlling direction and speed, braking, and landing. Wing feathers are spread and arranged for flapping, while subtle changes to positioning of a bird’s tail feathers allow it to change direction and slow down or brake when needed. The shape of a bird’s wings also affects its flight. Elliptical wings are more efficient than straight or rounded shapes and provide fast take-offs, bursts of quick speed, sudden and accurate turning, and steady balance when moving through air currents. High-speed wings are long and thin with tapered ends, making them perfect for high-speed flying, while broad soaring wings, seen in buzzards, are long and broad with deeply slotted wing tips that allow for maximum lift.
Elliptical wings are a characteristic of sparrows, while broad-soaring wings are commonly found in buzzards. When it comes to steering in flight, birds use a combination of body movements and wing adjustments to manoeuvre. Their tails act as a rudder and help with steering by allowing for subtle or sharp turns. Taking off from land requires birds to move against the airstream; they either take off into the wind or create their own airstream by running and jumping into the air while flapping their wings. Some birds, such as swifts, are weak at taking off due to underdeveloped feet. Instead, swifts drop into the air from a ledge after a rare rest.
Have you ever wondered how birds take off from water? It’s actually quite similar to how they take off from land! Ducks and geese start by flapping their wings as they run at a high speed across the surface of a lake or sea. The goal is to get enough air moving fast enough to produce lift. Once they build up enough momentum, they are lifted into the airstream and off they go!