Tails 409 
We notice that birds which have very short tails are 
unable to turn quickly and that their flight is very direct, 
or even where there is a long tail, if it is principally for 
ornament and not well muscled, it is of little use in help- 
ing its owner to change the direction of flight. The 
partridge-like tinamous of South America are good exam- 
ples of the first-mentioned group. Their tails are small 
and useless, and when once the bird launches itself into 
Fie. 324.—Tail of Pelican alighting. Fig. 325.—Tail of Tern in flight. 
the air, it can keep on only in a straight line and is at 
the mercy of every cross-current of air. A more familiar 
case, which any one may observe, is a Song Sparrow, or 
other small bird, which, from accident or from some irregu- 
larity of moult, has lost all or most of its tail-feathers. 
Instead of rising with the strong, darting flight with 
which such a bird is accustomed to make its escape from 
our path, its flight under such conditions is weak and 
direct, like the trial efforts of a young bird. 
