You may not think of birds as one of the giant wonders of the world, but have you ever wondered just how do birds fly? Well, the answer may make you rethink your opinion on birds! The way birds fly is a marvel of evolution, involving perfectly developed features, interesting bone structure and a little help from gravity.
So, if you’re questioning ‘how do birds fly?’, we have the answers you’re looking for! So, let’s take a look at what makes birds fly and the different types of flight for which they evolved.
How Do Birds Take Off?
Of course, before we answer, ‘how do birds fly?’, we need to be aware of how they get up into the air in the first place! Fortunately, understanding how birds take off is probably the easiest part of the process.
Birds take off with an action known as thrust, involving flapping their wings and making use of their small, firm muscles to lift themselves from the ground. Birds often take off from a running position to give them extra thrust into the air.
How Do Birds Fly?
So, now we know how they get into the sky. But just how do birds fly? Discovering the science behind this little wonder may not be as mind-boggling as you think!
Birds’ wings are flat and streamlined, allowing the air to flow freely around them in the direction that the bird is flying. As a bird’s wings are curved along the top, the air flows quicker over the top of the wing than it does at the bottom; so, there is more air on the bottom side of the wing since it is moving slower than it is on the top side.
This slow-moving air around the bottom side of the wing creates a pushing force that pushes against the flat surface area of the bottom wing. And this is what lifts the bird.
With a bit of help from gravity, this pushing force allows birds to fly through the air.
What Features Help Birds Fly?
Although we now know the answer to ‘how do birds fly?’, there are several things that help them get into the air, particularly aspects of their physical body. Most birds are designed for flight. Their lightweight feathers and streamlined body evolved to allow them safe, quick passage through the air, the same way we evolved for walking on two legs. However, there are many more natural features of birds that help them fly. Take a look at the main attributes of birds and how they aid their ability to fly.
||How It Aids Flight
||Strong, shaped wings enable birds to lift themselves off the ground and into the air
||Reduces the force of the wind and drag
|Smooth, lightweight feathers
||Reduces the force of the wind and makes birds more aerodynamic
||Replaces heavy bone structures and reduces the force of their weight
||Hollowed, strong bones reduce a birds weight and makes it easier for them to lift off
||Provides solid attachments for flight muscles
|Enlarged breastbone (sternum)
||Helps with the force of thrust and provides a larger surface area
Different Types of Flight
Birds have several different types of flight that they use in different situations. For example, if you spot a flapping bird, it’s likely on a hunt or on the run from a predator. However, if a bird is gliding, it doesn’t feel as though it is in danger and is able to relax as it moves. Gliding, soaring and flapping are three main types of bird flight, and here’s the difference between them:
During gliding, a bird doesn’t have to do much work. A bird holds its wings out to the side of its body without flapping when gliding. While the bird moves through the air, it holds its wings at a slight angle, deflecting the air downwards and creating lift. However, since the bird’s body creates air resistance, the bird has to tilt forward regularly to help it maintain speed and direction.
Soaring is a different type of glide where the bird flies using a thermal, or rising air current. Since the air is rising, this helps the bird to maintain its height in relativity to the ground. For example, albatrosses soar during their long voyages out at sea for migration.
Flapping is the form of flight that you are likely most familiar with and involves birds flapping their wings in an up and down motion. This movement propels them forward. A bird’s wingspan has to be at the right angle of attack to successfully fly in this way, meaning the wings automatically twist with each downward flap to align the bird with the right direction of travel.
Similarly to during take-off, flapping requires lift and thrust, which the bird’s wings create with each downstroke. With every upward stroke, birds partially fold their wings to allow them to pass through the air with little resistance.
Do All Birds Fly?
No, not all birds fly. For example, penguins are birds that lost the ability to fly during evolution in favour of more streamlined wing feathers to help them move quickly through water and catch fish. Of course, there are many other birds that can’t fly and evolved to survive in different environments, including:
On the other hand, some smaller birds can fly but in different ways. For example, small birds, like sparrows and kestrels, can hover for a limited time since their wings are so small. They can do this by flapping their wings to generate thrust without using energy to move through the air.
Finally, many smaller birds use their tails to aid their flight. Their tails work like fins on aeroplanes to create air resistance and drag so these birds can slow down quickly.
Answering How Do Birds Fly
Now you know just how much of a wonder birds truly are! ‘How do birds fly?’ is an interesting question with a just as interesting answer, and we hope you feel like an expert on the wonder of bird flight now.
Do you have any more questions relating to how do birds fly? Let us know your thoughts in the comments below.
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