
world. If I put a penny in the peanut vendor, he 
will dash in for his share. If I thrust a foot 
out quickly, he will evaporate in a blur of wings 
to reappear on the platform across the tracks. 
Little wonder that there is scarcely a place in 
the world today where birds do not live. They 
signify the triumph of their type—for today the 
giants of the Age of Reptiles have been extinct 
for 100 million years. 
But, for all their bright colors and songs, 
we may as well face the fact that birds are only 
glorified reptiles, and feathers are nothing but 


may have developed elongate scales at the trai l- 
ing edges of the limbs, permitting a prolonged 
leap or even glide. But once they really hit on 
the winning combination and produced the miracle 
we call feathers, the sky was literally the lim- 
it. The air was full of insects and there was 
hovéreature on earth that could eat them. 
SOME ‘BIRD HISTORY 













ruled by giant reptiles. 
its head about, looks me up and down with beady 
eye. Easy to see he is unabashed in this man- 
specialized scales. Many of the bird-footed din- 
osaurs, which were often no larger than chickens, 







Archaeopteryx simply Seales out too mete front 
and rear and its skeleton was too loose. Modern 
birds have rib cage and backbone fused into the 
light, strong fuselage needed to anchor powerful 
wings. The skull is light, having lost the rep- 
tilian teeth of the original model, and is well- 
balanced by fused and telescoped tail vertebrae. 
Feathers make the bird but feathers alone do 
not make birds fly. 130 million years of race- 
history were focused on the project of creating 
a successful flying machine. Needed were warm- 
bloodedness, high energy output (metabolism) and 
a brain that places co-ordination above reasoning. 
Birds have all these things. They eat contin- 
uously and have normal temperatures between 102 
and 112 degrees Fahrenheit, compared with our own 
98 degrees. They have large, 4-chambered heart s— 
extremely massive muscles. The breast muscles, 
which power the wings, may weigh a fifth of the 
total weight of the bird. 
The heart, which cycles the blood completely 
through arteries and veins every second or two, 
a 
THE EVOLUTION OF BIRD FLIGHT MODERN FLYING BIRDS 
ARCHAEOPTERYX ‘was a glider. have a large keel end 


iL gee. éx, It had no keel which rigid rib-cage with fu- 
Pcie RLS Sit “Mimodern birds need to # sion of vertebrae. The 
A e inte = ry" SIE Y ye a fasten their wing dt untoothed skul] 
Z on i hy =: {' = ve Le muscles. Skeleton #7 —& and telescoped 
on SANE Wiese aaAN ft SSx was loose, toothed ff tail vertebrae 
ag i rp Up ise: 1 \W ns skull and tail tooaf are very light. 
CE Je Aes 
Gi S.. = Ws i ree i \ Sh he 
ARCHAE- \ 5 1 - x fe a NN no keel ia WW 5 | 
OPTERYX ne 1 F . = Giue N* 
(ancient wing) wer: i M NN 
goo f i BIRD-FOOTED DINOSAUR 
The first known bird ex- Ry® a ieee ra ai : Many dinosaurs were no . keel 
isted 130 million years iT As NAVA larger than chickens. < 
ago in a tropical world ( CO I PEM DTG It is from this stock x 
that birds arose. 


