The Physics of Bird Flight

The Physics of Bird Flight
5th Grade
• To explain how a bird is able to fly
• To identify three types of flight that birds use.
Did you know?
• All objects on land are surrounded by an
invisible ocean of air.
• Air = a mixture of gas molecules that exert
pressure on the objects they surround.
Air Pressure:
• When you blow into a balloon, it gets larger
• The pressure of the air molecules pushing on
the sides of the balloon make it expand
Air Pressure: How does it work?
Air Pressure: How does it work?
Air Pressure
• The faster air moves, the less pressure it
Movement and Air Pressure
For birds, fast-moving air above the wing exerts
less pressure
Slower-moving air below the wing exerts more
Higher pressure keeps the bird in flight
A bird’s angle and shape of the wing
causes the air to move faster above
the wing than below it
Lift: an upward force that causes a bird
to rise based on the difference in
pressure above and below the wings
as a bird moves through the air
What does a bird do to get off of the
ground before it uses lift to fly?
To get into the air….
• A bird moves forward to make air move over
its wings
• A bird sharply pulls down its wing to provide
the power that pushes the bird forward
Once birds are in the air, there are 3
types of bird flight
• 1) ?
• 2) ?
• 3) ?
Three types of bird flight:
• 1) Flapping
• 2) Soaring
• 3) Gliding
Flapping: what does that do?
• All birds flap their wings (sharply pull down
their wings)
• Certain birds rely on flapping more than
• Involves little movement
• Birds use rising currents of warm air
• Used to move upward
• Involves little wing movement
• Birds use falling currents of cool air
• Used to move downward
Question: Does Soaring or Flapping
take more energy?
Answer: Flapping…it takes a large
amount of energy!
What do birds use so that they do not
need to waste too much energy on
They use warm and cool air currents
Did you know? Warm air rises and cool
air sinks
Remember that to soar, birds use
warm air currents so that they can
move upward
Remember that to glide, birds use cold
air currents so that they can move
What is a type of flight that we have
not yet talked about that doesn’t use
any lift?
Answer: Diving does not use any lift.
• How do birds use diving to their advantage?
Diving is used for…
• Hunting for prey
What does a bird do with its wings so
that it can effectively dive?
Birds pull their wings in close to their
bodies so that there is no more lift
• The result: gravity pulls them down!
• Fun fact: Peregrine Falcons can dive up to 300
kilometers per hour
Peregrine Falcon Diving
Bird Flight: This video really helps
explain it!