Birds: Concept of Flight

How Do Birds Fly?

Birds have special adaptations that help them fly.

• Wings: Birds’ wings are shaped like an airfoil, bigger up front and taper towards the back. 
  • Air flows over and under a bird’s wings. The air on top pushes less on the wing than the air on the bottom. 
  • The wing moves upwards, and this push is called “lift.” This helps them rise up. 
  • Birds rotate their wings forward and down and then up again. This rotation helps them move forward, and this push is called “thrust.” 
• Muscles: They have powerful flight muscles attached to their breastbone. These muscles help with the flapping of the wings.
• Bones: Birds have a lightweight skeleton. Their bones are hollow, with a lot of air spaces inside them. This lightweight frame helps them counteract gravity. 
• Feathers: The arrangement of feathers helps control airflow.
• Respiratory System: Birds have lungs and internal air sacs that help with the one-way flow of air to supply oxygen during flight.

V-Formation Flying

Birds usually fly in a V-formation when traveling long distances. 

• In a V-formation, the birds position themselves slightly behind and to the side of the bird in front of them.
• Flying in a V-formation reduces air resistance. The bird flying behind another bird has to spend less energy to fly. 
• The V-formation helps with communication and coordination among the flock.

Flying in the Rain

Birds mostly avoid flying in the rain and take shelter.

• The feathers of most birds are not 100% waterproof. The feathers become heavy when they get wet, making it harder to fly.
• Feathers also provide insulation to keep the birds warm. When the feathers get wet, birds can get cold. 
• The flight muscles must work harder to move the wings when the feathers get wet.
• Dense air gives birds the lift needed to fly. When it rains, water molecules in the air make it less dense, so more energy is required for flying.

Fun Facts

Here are some fun facts about the flight of birds:

• Bar-tailed Godwit holds the record for the longest flight (6800 miles) from Alaska to New Zealand without any rest. 
• The Ruppell’s griffon vulture is the world’s highest-flying bird, reaching heights over 36,000 feet above sea level.
• The hummingbird is the only bird that can fly in any direction. The unique architecture of its wings enables it to fly forward, backward, straight up and down, or to remain suspended in the air.
• The peregrine falcon can achieve the greatest airspeed of more than 200 miles per hour in its dives.

Review

Let’s quickly recap what we learned about the concept  of flight:

• What is the shape of a bird’s wings that helps with flying? Airfoil
• What is unique about the bones of birds that enable them to fly? Hollow to make them lightweight
• In addition to lungs, what does a bird’s respiratory system have to provide a constant oxygen supply? Internal air sacs
• Which bone of a bird’s body is attached to the powerful flight muscles? Breastbone