132 STUDIES IN BIRD-MIGRATION 



It frequents much the same haunts as the Willow- 

 Warbler, and has the same habits, but is always 

 silent. 



Phylloscopus tristis, Siberian Chiffchaff. — -This is 

 the latest of all the Warblers to make its appearance at 

 Fair Isle, where it has appeared regularly during the 

 autumns of the past four years. It has, as yet, only 

 once been detected on its passage northwards in spring, 

 namely, on the 7th of May 1909. 



The earliest dates on which it has been known to 

 appear during each of these four seasons are on 8th 

 October in 1908, 15th October 1910, 21st October 

 1907, and 30th October 1909. The latest date on which 

 it has been observed in the island is 6th November. In 

 all about a score have been obtained ; but it is not very 

 uncommon in most seasons. I only once had the 

 pleasure of seeing the bird in life, namely, on 8th 

 October 1908, my visits on other occasions having 

 come to an end ere it arrived. George Stout, who has 

 seen quite a number of them, considers this to be the 

 tamest species of Phylloscopus visiting the isle. He 

 found the birds chiefly in the cabbage-plots, the only 

 cover in the late autumn, where they were' sometimes 

 seen in company with the Northern Chiffchaff. On 

 some occasions he saw several together ; and on fine 

 days they perched on the cabbage leaves, every now and 

 then darting into the air to capture insects, and returning 

 to their perch. They were also observed searching for 

 flies on the face of the cliffs, on peat banks, and on old 

 lichen-clad walls. Elsewhere in Britain, it has only 

 been known to occur at Sule Skerry, in Orkney in the 

 winter of 1907-8, and at the Isle of May on i6th October 

 1910. 



