BONELLl'S WARBLER IN SWITZERLAND. 243 



and the Wood-Wren that neither of them ever uses feathers for 

 the lining of the nest. I have only once been lucky enough to 

 find the egg, i. e. on June 15th, 1889 ; as a rule, I have been 

 too late in reaching Switzerland. My note records that this 

 was a beautiful one, dull white in ground colour, with rich 

 chocolate-coloured spots, chiefly at the larger end. This agrees 

 fairly well with Prof. Fatio's description of the egg, except that 

 he writes of the spots as being " gris et bruns." 



This year, June 8th, I found Bonelli again rather higher on 

 the steep hillside above Thun ; the old familiar gentle sibilation 

 caught my ear at once in the hazels, and while we waited, the 

 bird, doubtless the male, continued to move about from point to 

 point without once letting you see it. The hen, I imagine, was 

 on the nest, and when this is the case, her consort seems to be 

 constantly on the move, sometimes retiring to a distance for a 

 few minutes, then returning, but never betraying the situation 

 of the nest. All the time the gentle sibilation goes on ; some- 

 times with notes distinctly uttered, almost recalling those of the 

 Lesser Whitethroat (only never so loud), sometimes so hurriedly 

 as to become a kind of subdued hiss. Fatio syllables the sound 

 as " pi-hui-hui-hui," or simply " hui-hui-hui-hui " ; but, as a 

 rule, the repetition of the note is more frequent, in my experience, 

 and I should prefer to write at least five or six of these " hui's." 

 They are something like the slower notes at the end of the 

 Wood- Wren's song; and it was interesting to find this latter 

 bird five minutes' walk further on, and so to be able to compare 

 the two utterances. Bonelli has not the loud sweet call of the 

 Wood-Wren, but the alarm-notes of the two are much alike 

 (thui, as Fatio renders them), and I found later on this year 

 that, when really alarmed for a nest containing young, Bonelli 

 can utter a louder wail which is almost enough to induce even 

 an enthusiast to abandon his search. The nest of the bird I 

 have just been describing escaped me ; it probably contained 

 eggs, and when that is the case, the difficulty is great, owing to 

 the hundreds of suitable spots all around you of which one is just 

 as likely as another to be the right one. When the eggs are 

 hatched, the birds are so busy with the work of feeding that they 

 readily betray their secret. 



So at least I found a day or two later, June 11th, when we 



u 2 



