292 STUDIES IN BIRD-MIGRATION 



Tomison, emigrate, as their numbers do not seem to 

 increase. I have no doubt the Merlin exacts a heavy 

 toll from this species. 



Regulus regulus, Goldcrest. — As at all far- 

 western stations, so at Sule Skerry, this well-known little 

 bird is a very uncommon visitor. During eleven years it 

 has only been recorded as having appeared on four 

 occasions, all in autumn. These visits date from 29th 

 September to 15th October, and relate to few individuals, 

 fifteen being the largest number seen. 



TuRDUS Musicus, Song- Thrush, — Occurs occasionally 

 on passage in autumn, sometimes in rushes, but has 

 very seldom been seen in spring. The data for autumn, 

 which are slight, indicate that the movements are 

 performed from 25th September to 24th October. 



TuRDUS ILIACUS, Redwing, — A visitor during its 

 passages, which are recorded for spring from 31st March 

 to 22nd May, and in autumn for 20th September to 

 14th November. In the former season these visits are 

 most frequent, and the migrants most numerous, 

 during April ; and at the latter great rushes are 

 witnessed from mid-October to early November. 



TuRDUS PILARIS, Fieldfare. — Is a visitor during the 

 autumn passage, occurring in October and November, 

 sometimes in great rushes. The earliest date for its 

 appearance is 5th October in 1905. In spring it is 

 seldom noticed, the dates of the few records ranging 

 from 9th April to 6th May. It has appeared on a few 

 occasions in December and January, during snow and 

 severe weather. 



TuRDUS MERULA, Blackbii^d.- — Appears, sometimes in 

 great numbers, in autumn, at dates from 8th October to 

 14th November. It is less numerous on the spring 



