A Guide for the Study of Animals Part 43

Supplementary Studies of the Pigeon

These topics and questions should be answered from experience with pigeons and observations of their habits and behavior, and from books to be obtained from the school and public libraries.

1. The homing instinct of the common blue pigeon and of carrier pigeons.

2. Nesting habits, number of broods and number of young in each brood, feeding the young. Why is this method of feeding the young necessary?

3. Varieties or breeds of pigeons. How the various varieties were produced; how they are kept true; reversions of type.

4. Darwin's experiments with the pigeons; object of the experiment.

Whitman's experiments.

The Exoskeleton of the Bird: Plumage

_Materials._

Living birds, as perhaps pigeons, or mounted or stuffed skins, separate feathers, portions of feathers, microscopes.

_Observations._

The pupils should study the arrangement of the feathers and their variations in form and size, and should identify the following princ.i.p.al kinds:--

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

_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.

_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.

_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 a.s.sign 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 ill.u.s.trate Distribution_

Work in the Laboratory

_Materials._

Bird skins or mounted birds, at least one representative of each order and, better still, of each family of the birds which pa.s.s through or remain in your neighborhood; specimens in a museum may also be used. Some guide to the identification of birds, as Walter's "Wild Birds in City Parks" or Reed's "Bird Guide." A good diagram of a bird.