TOPIC: BIRD FEATHERS
LEVEL: Intermediate/Advanced
"The Feathers of Birds Flock Together"
[information |
preparation |
activity ]
- SCIENCE CONCEPT:
-
Birds have between 1,000 and 25,000 feathers, depending
upon the species. Obviously, larger birds have more feathers. The swan
with its long neck has the most. Feathers can be divided into six
categories. Students will be introduced to the various feather types and
study them under a magnifying glass.
- STUDENT OBJECTIVE:
-
For the students to learn the function of the six
categories of feathers. After viewing the different types of feathers
under a magnifying glass the students will draw them on artist paper.
This will give them a first hand view of the feathers that make up the
outer scaling of birds and how these feathers contribute to the ability
of a bird to fly.
- OVERVIEW:
-
The fascination with natural flight is a phenomenon that has
always captured the minds and imaginations of people. In studying the
feathers of birds students will have a closer look at part of the
elements that make up the bird's ability to fly. Feathers can be divided
into six categories so there is an abundance of viewing for the students
to participate in.
- TEACHER TEXT:
-
Feathers can be divided into six categories. The contour
feathers are the most abundant and cover the outer surface of the bird,
giving the smooth, sleek profile so important to flight. All contour
feathers have the same basic structure, with modifications depending upon
placement and function. There is a central rachis, or shaft, which is
hollow. Inside, dried remains of the pulp form strengthening struts
which run crosswise like ladder rungs. The vanes are the two halves of
the feather that spread out from the shaft. They are made up of hundreds
of branches called barbs, angling toward the tip of the feather. Each
barb has tiny, parallel branches of its own called barbules. The vanes
are smooth because of the structure of the barbs and barbules. As the
feather bends and twists during flight, the barbule hooks slide back and
forth retaining the smooth but flexible shape. However, a reverse twist
from the tip to the base will separate the barbs and make the feather
ragged with spaces in between. Preening "re-zips" the barbs and
barbules. The barbs at the base of a contour feather have no hooks and
so they appear fluffy.
The second type of feather is the semiplume. It is
shaped like a contour feather, but its' shaft is not as stiff and its'
barbs have no hooks so are fluffy. The third type is the down feather.
It is fluffy like the semiplume but has a very short shaft. Both the
semiplume and the down feathers are important for keeping the bird warm.
The fourth feather type is called the filoplume. These are tiny and
delicate with only a few barbs on the tip. They are sparsely scattered
among the other feathers. Bristles are stiff, hairlike feathers found
only in some birds. This makes up the fifth category of feathers. Their
function is specific in each species. Bristles are found around the
mouths of birds who scoop insects out of the air. Bristles are found
covering the nostrils of woodpeckers, and in ostriches they form
eyelashes.
The sixth and last type of feather is only found in a few
birds. It is the powder-down feather. This feather grows continually.
The tip breaks off forming a water resistant powder. The metallic sheen
of the heron is caused partly by this powder down.
A bird's wing is the basic structure for flight. It is covered with the
contour feathers that are specialized for flight. It is the shape of the
wing that enables a bird to fly, and the shape is determined by the
feathers.
PREPARATION TIME: 20 minutes
LESSON TIME: 40 minutes
TEACHER PREP:
-
Gather as many of the six different types of feathers
for the students to view under the magnifying glass. Suggestions for
locating the feathers: call a local zoo with a bird sanctuary, contact a
pet store with birds, or a private resident who has their own birds.
WORDS TO KNOW:
- contour
- rachis
- shaft
- hollow
- pulp
- vanes
- barb
- barbules
- hooks
- semiplume
- down
- quill
- filoplume
- bristles
- powder-down
MATERIALS NEEDED:
- 6 types of bird feathers(or as many as possible of the various types)
- magnifying glasses
- artist paper
- pencils and erasers
- stapler
- STEPS TO FOLLOW:
-
1. Read through the material under the Teacher Text to the class and
discuss the concepts presented with the students.
-
2. Pair each student with one other student.
-
3. Hand out one magnifying glass and one set of 6 feathers to each team.
-
4. Give each team adequate time to view the feathers under the magnifying
glass.
-
5. As a class take time to discuss the variations and similarities of the
6 type of feathers.
-
6. Ask students to draw a picture of each type of feather and label.
-
7. Staple the pictures together of each student's art work of the
different feather types.
8. As an extra project ask the students to draw a picture of a bird and
use as the cover for their art work of the feather types.
-
- WHY?
-
The feathers of a bird are an engineering marvel. The
study of them can fascinate students and cause a greater curiosity. It
will hopefully motivate students to investigate further into the other
aspects that give birds the power and magnitude of flight.
- ASSESSMENT: Can the student communicate what they observed?
- 4....Student is able to demonstrate a knowledge of 5 of the varieties of
feathers on a bird through their drawings, labeling, and oral explanation
of the feathers' function.
-
3....Student is able to demonstrate a knowledge of 4 of the varieties of
feathers on a bird through their drawings, labeling, and oral
explanation of the feathers' function.
-
2....Student is able to demonstrate a knowledge of 3 of the varieties of
feathers on a bird through their drawings, labeling, and oral explanation
of the feathers' function.
-
1....Student is able to demonstrate a knowledge of 2 of the varieties of
feathers on a bird through their drawings, labeling, and oral explanation
of the feathers' function.