48 STUDIES IN BIRD-MIGRATION 



haunts where cover abounds, and thus few — very, very- 

 few — -come under notice. We should remember, too, that 

 we have not in the British Isles, where bird-watchers are 

 more numerous than elsewhere, anything like one daily 

 observer for every lOO square miles of country ! Small 

 wonder, then, that so very much escapes notice. It is 

 well to bear this in mind when drawing deductions from 

 migration data covering large areas. 



To return to Fair Isle : it must not be supposed after 

 a great immigration overnight, that birds will be in 

 evidence everywhere on the following day. This only 

 applies to species that show a predilection for the open 

 country, such as Fieldfares, Wheatears, Pipits, and the 

 like. The various species of Warblers, the Bluethroat, 

 Thrush, Blackbird — indeed, the majority of the arrivals 

 (I allude to the autumn) — are either in hiding among the 

 turnips, potatoes, and standing corn of the crofts, or are 

 quite beyond the range of observation on the face of 

 the great cliffs. 



The crofts are the great hunting-grounds, and 

 fortunately my numerous friends among the islanders 

 have most kindly permitted me to search their cultivated 

 ground. If this great privilege had been denied, the 

 labours of myself and my coadjutors would have been 

 well-nigh in vain. The crofts require to be searched 

 in a most thorough and systematic manner, for the 

 birds, being more or less exhausted by their long flight 

 overnight, lie very close among the variety of cover they 

 afford and are not easily discovered. When disturbed, 

 the migrants only fly a few yards ere they drop into 

 cover again— a trait which makes their identification 

 a matter of great difficulty, for one only gets a hurried 

 glimpse of them, and this, too, amid very unusual 



