DIRECTION OF THE MIGRATION FLIGHT 41 



S. viridana, have occurred three times, the Rustic Bunting more 

 than ten times, and White's Thrush more than fifteen times. 

 Moreover, from a hst of this length, comprising so many prominent 

 species, we may conckide with certainty that many others not 

 mentioned therein have visited the island without being observed ; 

 while the fact of such a large number of species having occurred 

 within so small an area as Heligoland seems to show that occur- 

 rences of this kind must be far more frequent every autumn in a 

 country so near as Germanj', as well as in central and western 

 Europe. 



If, now, we turn our attention to the spring migration, we shall 

 at once find that this is characterised, in all its various phenomena, 

 by striking differences from the great autumn movement which we 

 have just discussed. Here we nowhere meet with any attempt at 

 dividing the long migration flight into short convenient stages, 

 such as is often the case after the tirst great advance during the 

 autumn migration ; nor do the birds at this time anywhere 

 exhibit a tendency for taking long spells of rest in the course of 

 their journey. Unrest and an impelling haste are everywhere the 

 prominent characters of the movement during its whole progress. 



Of the migrants which have arrived before daybreak, or during 

 the early morning hours, many continue their journey after only a 

 few hours stay; by ten o'clock the majority have left the island, and 

 soon after noon almost exQvy one of them has disappeared. Should, 

 however, the weather promise to remain favourable, many others 

 will make their appearance in the course of the same day. Among 

 them flocks of Swifts are seen hmiying on, while Hooded Crows con- 

 tinue to pass over till sunset. On calm sunnj' days, during the later 

 hours of the afternoon, thousands of Curlews and related species 

 may be seen, at heights of thousands of feet, tearing along in rapid 

 flight from east to west across the island. Their clear calls are 

 scarcely audible from the immense height ; but not one of the 

 wanderers hesitates in his course, or shows even an inclination to 

 tarr}^ for one brief moment. 



Indeed, in fine and favourable weather there is at such times 

 scarcely a break in the great onward movement, for the passage of 

 the high-flying species towards evening is followed, during the quiet 

 interval of twilight, by that of the Song Thrushes, Redbreasts, Hedge 

 Sparrows, Golden-crested Wrens, and others which are resuming 

 their journey after a stay of a few hours or more, though, from 

 their having already repaired to the shrubs and bushes of the 

 gardens, one might have supposed they were intending to stay for 

 the night. Suddenly, however, through the stillness of the evening 

 there resounds the call-note of a bird as he rises on the wing. 



