MIGRATIONS OF BIRDS AT TUSKAR BOCK. 221 



migrations are on the whole fairly obvious, may be dealt with 

 more expediently on separate occasions. 



Diurnal Migrations of Wheatears, Willow -Warblers, 

 Chiffchaffs, and Spotted Flycatchers. 



It may be well, however, to consider now the diurnal move- 

 ments of a few well-known species, movements not so easily 

 detected. I shall confine my remarks to four species : Wheat- 

 ears, Willow-Warblers, Chiffchaffs, and Spotted Flycatchers. 

 The diurnal movements of others, mainly of less frequent occur- 

 rence, will, I hope, be considered subsequently. No bird figured 

 more prominently on the Tuskar Eock, as well as at the lantern, 

 than the Wheatear. This was especially so in the fall of the 

 year. And while more of these birds assembled together on a 

 given occasion round the lantern — naturally owing to the lure 

 with which they were presented — nevertheless the percentage 

 of observations made and specimens picked up on the Eock 

 in daylight was very considerable. I shall, however, avoid 

 now setting forth actual statistics; such will receive their 

 proper place when dealing exclusively with the migration of 

 the Wheatear. 



Unlike the preceding species just dealt with, neither the 

 Wheatear nor the three following birds now under consideration 

 appeared to adopt the custom when passing of descending 

 abruptly from a considerable height to alight on the Eock. 

 That they may migrate for a considerable distance at a fair 

 height above the surface of the sea is a question which I am not 

 prepared to consider in this paper. It would appear, however, 

 that, on sighting the Eock and wishing to alight, they descend 

 rather obliquely, and fly in over the waves until they reach their 

 perch. On a few occasions I have actually witnessed the arrival 

 of Wheatears, Willow- Warblers, and Chiffchaffs (not, however, 

 Spotted Flycatchers) along the outlying reefs. But owing to the 

 small size of these birds and the difficulty of "picking them up" 

 as they flew along over the ever-moving surface of the sea, I was 

 unable to say at what distance off they made the descent. In by 

 far the greater number of instances these birds had already 

 arrived unknown to me. Owing, however, to their extreme 



