VARIETIES OF WING AND OF .FLIGHT 101 



if we bear in mind that he carries his long legs 

 stretched out behind. But his breastbone is short 

 and deep, so that the great weight of muscle lies 

 forward. Occasionally he may be seen to extend 

 his neck full length, apparently for balancing pur- 

 poses. The Stork is long-legged and the Flamingo 

 still more long-legged, and both of them carry their 

 necks and legs straight out. This is the normal 

 attitude also of birds of prey. The Stilt, too, flies 

 with his marvellous legs streaming out behind him ; 

 his style of flight is well shown in a drawing in Mr. 

 Abel Chapman's Wild Spain. 



Flight in Flocks. 



When birds fly in a flock, great or small, they often 

 adopt a particular formation, very commonly that 

 of a V, and this is sometimes spoken of as if it had 

 some special merit. But really the only important 

 thing for each bird is to keep clear of the wash of 

 his predecessor and the broken columns of air that 

 he leaves behind him. The force of the wash is the 

 measure of the vigour a bird puts into his wing- 

 strokes ; it will not do, therefore, to travel close in 

 the wake of another bird. The bicyclist, on the 

 other hand, breaks the resistance of the air, and the 

 man who rides close behind another has an advantage 

 since he finds the air more yielding. As the man in 

 front is not riding on the air there is no back-current 

 behind him (see p. 4). 



The Whir of Wings. 



Everyone must have noticed the different notes 

 given out by the wings of different kinds of birds as 



