THE BIRDS OF FAIR ISLE 121 



have been confounded in the past, so that it is now 

 impossible to decide to which form the older records 

 should be assigned. 



MoTACiLLA THUNBERGi,^ Grey-headed Wagtail. — A 

 regular visitor in small parties in spring, and in 

 scantier numbers in autumn. 



The earliest record for its appearance in spring is 

 for 25th April ; but the dates between which it most 

 frequently occurs are from the second week of May to 

 the end of the month. The latest date is for 3rd June, 

 when several appeared in 1907. 



In autumn it has been noted between 26th September 

 and 9th October, and once on 4th November. 



It is an extremely wary species and very difficult to 

 approach, except when engrossed in capturing flies dis- 

 turbed by cattle. 



Anthus trivialis, Tree-Pipit. — Common on both 

 passages, though apparently overlooked elsewhere in 

 the Shetland area. 



The earliest date for its appearance in spring, on its 

 way northward, is 5th May. It is numerous from the 1 2th 

 of that month to first days of June ; and the latest date 

 for its appearance is loth of the last-named month. 



The return autumn movements are timed from 26th 

 August, and are frequent from the middle to the end of 

 September ; a few occur in October, sometimes as late 

 as the 22nd ; while in 1908 one was sent to me which 

 had been obtained on 9th November. 



The chief haunts of the spring migrants are the 

 grassy faces of the cliffs, on which they obtain food in 

 company with various Warblers. Though sometimes 

 frequenting the same ground, it seldom keeps company 



' Motacilla flava thunbergi. 



