But if any be demanded it may be furnished by the carrier 

 pigeon, which has been known to maintain a speed of 55 miles 

 an hour for four hours in succession : and it is extremely 

 unlikely that this is much, if at all, exceeded by any wild 

 bird during long-distance flights. 



That our spring and autumn migrants must possess 

 wonderful powers of endurance is beyond question. And it 

 is equally certain that thousands must perish by the way. 

 By this means is the standard of flight maintained — ^the weak 

 perish. Even the minimum standard of efficiency for the 

 survival of such an ordeal must be a high one. 



Few of us see anything of these marvellous migration 

 flights. For, in the first place, they are generally performed 

 at night, and at a great height, often beyond the range of 

 human vision. Only as they approach land, and their 

 destination, do they descend. American naturalists have 

 made some interesting observations by directing a telescope 

 against the sky. Thus, Mr. Frank Chapman, by turning 

 his instrument towards the full moon, has seen birds passing 

 at night at an altitude, according to his computation, of 

 five miles : while the late Mr. W. E. D. Scott saw, through 

 an astronomical telescope at Princeton, New Jersey, great 

 numbers of birds passing across the face of the moon — 

 warblers, finches, and woodpeckers among them. Mr. 

 Chapman again, on another occasion, saw no less than 262 



44 



