20 Mr. J. Black wall's Ornithological Notes. 



nessing the fascinating effects ascribed to the music of this ima- 

 ginary siren. 



The red-backed shrike may frequently be seen to take insects 

 when on wing, like the Muscicapidce. 



The Whinchat, Saxicola ruhetra. 



In Denbighshire this pretty migratory bird arrives about the 

 end of Aprilj when the song of the male, which is sometimes 

 delivered on the wing, may be heard repeated at short intervals. 

 After the female has hatched her eggs, both sexes commence 

 the call from which the species receives in Lancashire, where it 

 is abundant, the provincial name of utick ; the accent falls on the 

 note supposed to resemble the first syllable of the word, and the 

 second note of the call is sometimes repeated; thus, — utick tick. 



I have seen the whinchat pursue the red-backed shrike with 

 cries and gesticulations expressive of extreme animosity. 



The Sedge Warbler, Sylvia phragmitis. 



The late cold spring of 1847 exercised a very marked influence 

 upon the vocal powers of our migratory warblers ; the notes of 

 the sedge warbler, which were not heard in the neighbourhood 

 of Llanrwst till the 14th of May, were so defective in tone that 

 this species found it quite impracticable to execute its song, 

 being enabled by the most strenuous efforts to perform a few 

 passages only, and those in a very imperfect manner; even the 

 high powerful strain of the black-cap, Sylvia atricapilla, and the 

 deep rich melody of the garden-warbler, Sylvia hortensis, were 

 reduced to a few short, abrupt, feeble sounds without any ap- 

 parent connexion or modulation ; our resident singing birds also 

 were sensibly affected by the severity of the season, all attempts 

 to deliver their lays with their accustomed vigour and facility 

 being totally unavailing. As the temperature increased with the 

 advancing year, a corresponding improvement was perceptible in 

 the wild music of the fields and woods, until the full flow of song 

 announced the pleasing intelligence that the summer was at last 

 confirmed. Now as it is evident, from the facts already stated, 

 that a relation must exist between the singing of birds and the 

 temperature of the atmosphere, I shall briefly advert to some of 

 the circumstances which appear to constitute that relation. 



An idea seems to have been entertained by the Honourable 

 Daines Barrington that the periodical cessation of the songs of 

 birds may possibly be caused by some physical impediment, as 

 indicated by the following paragraph extracted from the fifth 

 letter addressed to that gentleman by Mr. White in his 'Natural 

 History of Selborne :' — " Your supposition that there may be 



