The ability to fly is one thing us humans have fantasized about for all of history, and have achieved ourselves through technology. But the way an animal like a bird or insect is built and evolved to fly still intrigues many, often wondering what life would be like if we could fly this way too. How exactly do these animals fly though...is it just the wings? Or their weight? Or a combination of more factors? Well let's take a closer look and learn the truth behind how birds fly:
- Bird Flight is often considered one of the most complex forms of movement in the animal kingdom, as every aspect from taking off/landing, hovering, and changing speed all involves many complex actions.
- How birds evolved flight is actually still hotly debated, and there are 2 main theories on how this happened. One is called the "trees down" hypothesis, and claims that flight evolved from gliding and falling. The other is called the "ground up" hypothesis and claims flight evolved from running and leaping. Many scientists and scholars also believe in slight variations on these hypotheses.
- Many birds have hollow bones, especially in their wings, or different density and weight to the bones than most would expect as this helps keep their body a lighter weight.
Obviously, the wings of a bird are a fundamental necessity to their ability to fly. The physical forces of gravity, thrust, and lift, are all involved as well for these animals to soar through the air. Bird Flight can be broken down into 4 main steps for the bird to travel where it needs to go:
- The Take Off - While crouching, the bird unfolds its wings and jumps into the air, while their wings create a strong downstroke to lift the entire animal. The specific movements the bird makes and the curvature in their wings allow for flight to be possible.
- Flapping/Flight - Once enough speed has been obtained, air pushing against the wings continues lifting the animal. Flapping their wings creates forward thrust to continue their momentum while the air pushing against them continues to give the animal lift.
- Gliding - The streamlined body shape of a bird allows it to use that momentum its built to glide through the air, minimizing the air resistance. The bird does not flap its wings while gliding, and instead their primary and tail feathers are used to help steer and control speed, as well as keeping them stable.
- Landing - Many larger bird species prefer to land on water as it can often be easier to reduce their airspeed and momentum. Another option many birds try is aiming their landing below the area they want to reach (such as their nest) and then pulling upwards before landing to completely reduce the airspeed.