=Control of Flight.=--Did you ever see a bird sitting on a swinging
limb? What was its chief means of balancing itself? When flying, what
does a bird do to direct its course upward? Downward? Is the body level
when it turns to either side? Birds with long, pointed wings excel in
what respect? Examples? Birds with great wing surface excel in what
kind of flight? Examples. Name a common bird with short wings which has
a labored, whirring flight. Is its tail large or small? Does it avoid
obstacles and direct its flight well? Why or why not? When a boat is to
be turned to the right, must the rudder be pulled to the right or the
left? (The rudder drags in the water and thus pulls the boat around.)
When the bird wishes to go upward, must its tail be turned up or down?
How when it wishes to go down? When a buzzard soars for an hour without
flapping its wings, does it move at a uniform rate? For what does it
use the momentum gained when going with the wind?
[Illustration: FIG. 300.
_a_, clambering foot of chimney sweep; _b_, climbing foot of
woodpecker; _c_, perching foot of thrush; _d_, seizing foot of hawk;
_e_, scratching foot of pheasant; _f_, stalking foot of kingfisher;
_g_, running foot of ostrich; _h_, wading foot of heron; _i_, paddling
foot of gull; _k_, swimming foot of duck; _l_, steering foot of
cormorant; _m_, diving foot of grebe; _n_, skimming foot of coot.
=Question:= Does any bird use its foot as a hand? (Fig. 320.)]
=Flying.=--When studying the quill feathers of the wing, you saw that
the wider side of the vane is beneath the feather next behind it.
During the downward stroke of the wing this side of the vane is pressed
by the air against the feather above it and the air cannot pass through
the wing. As the wing is raised the vanes separate and the air passes
through. The convex upper surface of the wing also prevents the wing
from catching air as it is raised. Spread a wing and blow strongly
against its lower surface; its upper surface. What effects are noticed?
Study the =scales= on the leg of a bird (Fig. 300). Why is the leg
scaly rather than feathered from the ankle downward? Which scales are
largest? (Fig. 300.) How do the scales on the front and back differ?
What can you say of the scales at the bottom of the foot; at the joints
of the toes? Explain. How does the covering of the nails and bill
compare in color, texture, hardness and firmness of attachment with the
scales of the leg?
[Illustration: FIG. 301.--AN ALTRICAL BIRD, _i.e._ poorly developed at
hatching. Young pigeon, naked, beak too weak for eating.]
[Illustration: FIG. 302.--A PRECOCIAL BIRD (well developed at
hatching). Feathered, able to run and to pick up food. Precocity is a
sign of instinctive life and low intelligence. A baby is not precocious.
=Question:= Is pigeon or fowl exposed to more dangers in infancy?]
=Draw= an outline of the bird seen from the side. Make drawings of the
head and feet more detailed and on a larger scale.
Public-domain text, read in full here on John Shaqi.
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