TOPIC: ADAPTATIONS OF BIRDS
LEVEL: Intermediate/Advanced
"The Flight of Birds"
[information |
preparation |
activity ]
- SCIENCE CONCEPT:
-
Birds have certain characteristics that set them apart
from other animals. They have adapted to their environment, making them
prime subjects of flight. There are many reasons why birds are able to
fly.
- SCIENCE OBJECTIVE:
-
The student will be researching the characteristics
of birds, their adaptations to the environment, their wonderful ability
to fly, and why they are important to us.
- OVERVIEW:
-
Think for a moment about the variety of birds that you have
seen. Every bird has its own special color and flight ability. There
are many kinds of birds, yet they have certain basic characteristics.
Birds are well adapted for flight because they have two wings, have
lightweight bones, and breathe through lungs. Each kind of feather on a
bird serves a different purpose. Soft down feathers grow close to the
skin. Air is trapped between the spaces of these down feathers. The
bird's body gives off heat that warms the air in these spaces. Over the
down feathers is a second kind of feather that rounds out a bird's
streamlined body. A third kind of feather, the large flight feathers,
grow in the wings and tail. The flight feathers give birds the lift and
balance needed for flying.
The energy needed for flight comes from food and a steady supply of
oxygen. Birds' lungs branch into hollow spaces called air sacs. Air
from the lungs is pumped down through the air sacs. The air sacs
connected to the lungs supply oxygen during flight. Most birds secrete
an oily substance which they use to coat their feathers. This is called
preening and prevents water from penetrating their feathers, thus making
the birds buoyant. Birds' feathers are replaced at least once a year by
molting.
- TEACHER TEXT:
-
There are many things about birds that make them good
subjects for study. They are very abundant, so they are easily observed.
They adapt easily to captivity and experimentation. Their great
diversity with beautiful colors, characteristic songs, and unique habits
makes each species easily identifiable. In fact, it is probably the
great diversity among birds that enabled scientists to truly understand
the complex combinations each species possesses and still achieves
flight. Every thing about every bird is designed for flight no matter
what combination of attributes they possess.
In order to understand natural flight in birds, one must
examine the structure of a bird. Exactly what makes a bird a bird? They
all possess common characteristics. Birds are unique in the animal
kingdom for two reasons. First, all birds have feathers. And second,
all birds live in a hurry. Everything about a bird is fast: they
breathe faster than any other animal, their heart beats faster, and their
body temperature is higher.
As inhabitants of the earth, birds have a special place
in the ecological world. They play a vital role in the balance of
nature: eating insects, agricultural pests, and other small animals;
while they, in turn, are eaten by many larger animals. Fruit eating
birds, because they do no digest seeds, are the primary seed dispersal
mechanisms for many plants. Hummingbirds help pollinate nectar producing
flowers. Seed eating birds do digest seeds, and by so doing, eliminate
millions of weeds from the earth. For man, birds have other values as
well. They are sources of protein as both eggs and meat. Feathers are
used for pillows, quilts and clothing.
PREPARATION TIME: 30 minutes
LESSON TIME: 45 minutes
TEACHER PREP:
-
Obtain pictures or slides of a variety of birds in
flight, a live bird, three different kinds of bird feathers (down,
contour, and flight), and different bones such as chicken, pork, beef and
bird.
WORDS TO KNOW:
- air sacs
- lift
- balance
- streamlined
- hollow
- down feathers
- contour feather
- flight feathers
- respiratory
- preening
- molting
MATERIALS NEEDED:
- notebook paper
- pencils and pens
- microscope
- projector (if using slides)
- STEPS TO FOLLOW:
-
1. Introduce a variety of birds in flight pictures. Ask the students to
identify similarities in the various birds you show them.
-
2. If possible, use a live bird to point out the location of each type of
feather (down, contour, and flight).
-
3. Ask the students to handle the various bones (chicken, pork, beef, and
bird.) Have them compare their weights to illustrate that birds have
very light-weight bones. Show the students a cross section of the bones
and point out that the birds' bones are less dense because of the air
spaces in them.
-
4. Discuss how the respiratory system in birds is designed to provide the
large amount of oxygen needed to produce the energy for flight.
-
5. Ask the students to list ways on their notebook paper how birds are
adapted for flight. Have them list as many characteristics that they can
of how the bird is built for flight. Discuss these characteristics
together as a class.
-
6. Pair the students up and ask each team to come up with at least 5
reasons why birds are so important to us.
- WHY?
-
A bird is a wonder of flight. Man had to unravel the
mysteries of flight. He had to first understand the forces on earth that
enable flight, and then to try and duplicate a bird's actions. It wasn't
until technology enabled him to develop an internal combustion engine
that he overcame the difficulty of minimum weight and maximum power,
something nature conquered long ago. Also, the invention of the slow
motion camera enabled man to capture the split second motion of a bird's
wing in flight. He could now see what had been impossible to see before,
and could master controlled flight.
- ASSESSMENT: Can the student communicate what they observed?
-
4....Student is able to communicate at least 5 characteristics of why a
bird has the ability to fly and 5 reasons why birds are so important to
man.
-
3....Student is able to communicate at least 4 characteristics of why a
bird has the ability to fly and 4 reasons why birds are so important to
man.
-
2....Student is able to communicate at least 3 characteristics of why a
bird has the ability to fly and 3 reasons why birds are so important to
man.
-
1....Student is able to communicate at least 2 characteristics of why a
bird has the ability to fly and 2 reasons why birds are so important to
man.