Flying in the Friendly Skies
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Flight requires a tremendous amount of energy, a light, strong skeleton, wings,
and feathers. A birds entire body is adapted for flight, including some internal
adaptations.
For starters, the bird has wings. A wing is very similar to a human arm. It has
a shoulder, an upper arm and elbow, a lower arm and writs, a hand with fingers and
a thumb. However, our hand is different as we have more bones and fingers that we
can move. A bird has a narrow hand with only two fingers that are joined together
so they can’t move, they can only move their thumbs. So what do birds and airplanes have in common? If you said the Bernoulli
Principle, you’re right! The Bernoulli Principle says that when air speeds up, it
pressure drops and has less force. Based on this principle, wings are curved to allow
air to flow faster above the wing then below the wing. The slower moving air
beneath the wing pushes harder and forces the wing to move upward, creating
enough force to fly which is called lift. A bird also has a lightweight body due to bubble like structures filled with air
inside the body. These air sacs, which are attached to the lungs, spread throughout
a bird;s body and into its bones. The air sacs help to cool the body and lessen the
body’s weight. Birds also have hollow bones that are fused together, eliminating the need for
heavy ligaments. Even though the bones are hollow, they have cross balance’s and
struts to help make them strong.
Strong muscles are also required to help a bird fly. Flight muscles are attached
to the keel, or the breastbone, of a bird. The outer set of muscles lowers the
wings, and the inner set raises them. The pectoral muscle of a bird makes up 25%
of its body. The top speed of a bird depends on its design. The vulture flaps its wing once
per second. A small bird flaps its wings 4 times per second. The hummingbird flaps
its wings 10 times per second and flies at 60 mph. Every bird can change their
speed, but has a top speed during flight.
The fastest bird is the peregrine falcon. It flies at 100 mph in level flight. When
it folds its wings against its body, the falcon can dive at 200 mph.
Some birds do not fly very much. They spend most of their time on the ground.
These birds are designed for protection on the ground. They are the grouse,
pheasant, and quail (as examples).
Most birds do not fly faster or higher than is needed. This is because it takes
too much energy to climb against the gravity. Also, there is less oxygen to breathe
and support the bird high in the air.
Some birds make sharp turns at top speeds. Others fly mostly in straight lines.
The difference is in their tail design. Because the tail is used like a rudder the
feathers are broad and stiff. These tail feathers open and close like a fan and move
up and down. They also twist to the left or right.
Birds that soar over land have wings that are broad and slotted. And birds that
soar over the water have long and narrow wings. !
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Flightful Questions (fantastic!!)
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What are the five things required for flight?
1.
2.
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5.
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6.
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Describe the Bernoulli Principle.
7. What do birds have in their body to help make them lightweight?
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8. What is unique about a birds bones that enable them to fly? _________
___________________________.
9. What is another name for the breastbone? ___________________
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10. What muscles are attached to the keel? _________________
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11. The largest muscle in a bird is the ______________ which makes up !
______% of a birds body.
12. What is the fastest bird? __________________________
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13. What is the function of the tail when a bird is in flight?
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14. A land soaring bird would have wings that are ___________________.
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15. What is the most interesting thing you learned about flight?