NOVEMBER 291 



(equal to forty- one and a half statute miles) per hour. 

 This is such a venerable incident that it may best be 

 consigned to the limbo of tradition. Still, in searching 

 more recent statistics, one arrives at estimates of speed 

 even more startling. Herr Gatke devoted fifty years to 

 observing and recording the movement of migratory birds 

 in passage through Heligoland, and came to conclusions 

 about their rate of travel which it is difficult to reconcile 

 with probability. Thus, take the single instance of a bird 

 possessing very moderate powers of flight, the northern 

 blue- throat (Cyanecula suecica), a creature having affinity 

 with the warblers and the thrushes. It breeds in Northern 

 Europe, and migrates in winter to Abyssinia and India, 

 yet it is exceedingly seldom that one can be seen in the 

 intervening countries. ' Heligoland is the first point,' says 

 Gatke, ' at which in the course of this [spring] journey it 

 is met with unfailingly every year in very large numbers. 

 . . . Like most birds, especially insectivorous species, the 

 blue-throat travels during the night, setting out at dusk 

 and ending its journey at daybreak, or immediately after 

 sunrise. Hence it accomplishes its flight of more than 

 sixteen hundred geographical miles from Egypt to Heligo- 

 land in the course of a spring night of scarcely nine hours, 

 giving the almost miraculous velocity of one hundred and 

 eighty geographical miles per hour.' 



After this astounding calculation (which I quote here 

 under all reserve) my own modest observation on a recent 

 occasion may seem tame indeed. If one were asked to 

 name a British bird of slow flight and sluggish wing-beat, 

 very likely he would name the heron. Deliberate as the 

 movement appears to the eye, the strokes amount to not 

 less than 120 to 130 per minute. As to velocity, tho 



