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 
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