232 Mr. R. Collett on Phylloscopus borealis. 



The indefatigable manner in which the male gives forth its 

 monotonous, but nevertheless strongly sounding, song is 

 almost incredible. The song consists, as I have previously 



remarked, of a single note, zi-zi-zi-zi , repeated 



unusually quickly, fourteen to sixteen times in succession. 

 After each song follows a short period of rest, which in the 

 height of the singing-time scarcely exceeds half a minute, 

 when it recommences its song again. The song of the diflPerent 

 specimens was almost precisely alike, but in some it might 

 sound a little more or less harsh than in others. Seebohm has 

 compared the song to the trill of the Redpole ; and this seems 

 to be a suitable description, although it appeared to me to 

 resemble more the first quick notes of the song of Sylvia 

 curruca. 



In these latitudes, where the day is but little lighter than 

 the night, the song might be heard at any hour and even at 

 midnight. A little after the middle of July most of the 

 males had ceased to sing, although at Matsjok once or twice 

 I heard the song so late as the 28th of that month. 



This species never occurs in great numbers ; but as each 

 male in a district does not conceal itself from notice, the 

 males are consequently more easily secured than the females, 

 which, as a rule, are somewhat difficult to obtain. After the 

 singing-time is past, the males are also but seldom seen ; 

 their characteristic and sharp call-note is then the only thing 

 to direct one's attention to them. This call-note can best be 

 described by a short and whistling " tseers,'' and may be 

 heard at a long distance. It does not closely resemble the 

 cry of any other northern bird, but is most like the note 

 which Cindus aquaticus utters during its flight. This 

 note is always heard when one approaches its nest or its 

 young. 



The food of P. borealis consists chiefly of mosquitos, which 

 at their breeding-time swarm in myriads in the birch- woods. 

 On two occasions I have found the larvse of a Cidaria or 

 other Geometrid larva in its stomach, as well as other soft 

 insects. 



Amongst the numerous specimens I have shot in Finmark 



