How To Study Living Animals


Observations.

The pupils should study the arrangement of the feathers and their variations in form and size, and should identify the following principal kinds:—

Contour feathers,

those feathers, generally broad, which cover the body, giving to it its outline and color herunterladen.

Coverts,

those feathers which cover joints, such as the joints of the wing and tail.

Primaries or pinions,

the long stiff feathers of the outside of the wing, used in sustaining the bird in flight herunterladen.

Secondaries,

the shorter, more symmetrical feathers lying next and over the primaries.

Down,

soft feathers found on young birds and next to the skin on some adults microsoft office kostenlos downloaden vollversion deutsch chip.

Thread feathers,

best seen about the eyes, ears, and beak.

Quill,

the bare stiff portion, one end of which is inserted in the skin. Examine its internal structure.

Vane,

the broad expanded portion, the part ordinarily seen on the bird.

Shaft,

the mid-rib of the vane.

Barbs,

the delicate outgrowths of the shaft making up the vane.

Barbules,

the subdivisions of the barbs, some of which are provided with hooklets. These may well be studied microscopically.

Questions.

1. How is the plumage arranged to offer least resistance to the air in flight? How does a bird sit when exposed to the wind?

2. In a column write the names of the parts of a feather, and opposite each part state its particular use.

3. Of what use are the hooklets on the barbules?

4. State and explain the peculiar position of the shaft of the primary feather; of that of a contour feather.

The plumage of many birds contains all stages of feather specialization, from down to pinion. Find as many of them as you can on your specimen.

5. What reason can you assign for the fluffy base and the compact end of the contour feather?

6. How much of the feather of a full-grown bird seems to be supplied with blood vessels? How does this bloodless or full-blooded condition affect the weight of the feather; of the plumage; of the bird?

7. How would the above condition affect the temperature of the blood and of the body? Would it tend to cool the animal or to conserve its heat?

8. Show how the air lying motionless amongst the plumage may serve the same purpose as that in the packing of a fireless cooker or a “thermos bottle.”

9. How would the above condition affect the growth and repair of the feather? What connection has it with moulting?

10. What kind of feathers forms most birds’ “baby clothes”? What kind forms the adults’ “underclothes”?

Suggested drawings.

a. A typical feather.

b. A feather of each kind.

c. A bird with wings outspread, showing positions of feathers.

d. The minute structure of a feather.

Birds and Migration

To illustrate Distribution