NOTES ON THE BIRDS OF BELGIUM. 155 



low down, so that I got good views of them. Bonelli's Warbler 

 is a coldly-coloured little bird when seen against fresh, young 

 green leaves, and at a little distance shows no yellow tints. The 

 range of this little bird in Central Europe does not appear to be 

 fully worked out at present. 



Hypolais icterina. — I met with about half a dozen birds in 

 wooded places, a wood, and a garden. The song is marvellously 

 varied, and the variations seem endless ; short phrases are tried 

 over three or four times sometimes, long ones only once : the 

 song is a running one to this extent. It is a very remarkable 

 and striking song, but I do not think it is a fine one, the notes 

 being usually very harsh, and wanting in mellowness and melody. 

 In the space of a quarter of an hour, during which the bird sang 

 continually, I could detect no mocking of other birds. There is 

 a characteristic sound about the song of this bird (shared in 

 some degree by at least two others of the genus Hypolais) by 

 which you can recognise it at once ; but the bird is sometimes 

 easy to see when you have once made out its greenish-yellow 

 tints against the foliage, and you can note its orange mouth and 

 throbbing throat. Here are some phrases I took down from the 

 song of the bird just mentioned: — " ts'quairk (grating and 

 twangy) tisk tisk ; sik sik sik, kik kik kik (high and shrill) ; 

 tsairk (low and quavering like the cry of young hawks) poo-it 

 poo-it; pit-it pit-it pit-it; tip tip tip; ti-op ti-op; pitch-it 

 pitch-it ; kip kip kip care ; it-care it-care ; ik-waya ik-waya ; 

 too-ay, too-ay too-ay; it-tay it-tay it-tay it-tay; wik wik zay " 

 (three times over). 



Acrocephalus streperus. — Two or three at some pools near 

 Givet (see below) ; and one singing in a willow bush on the 

 banks of the Meuse at Houx. 



A. turdoides. — Just below Givet, in some flat grassy waste 

 land, there are some large pools, perhaps partly formed by 

 digging material for banking in the river (which is locked). The 

 pools are partly grown up with thick beds of reeds, flags, and 

 other water plants, and thickets of willows of two or three 

 species, — some bushes eight or ten feet high. As I approached 

 the pools, and was still at a considerable distance from them, I 

 was attracted by some notes of a peculiarly guttural song, and as 

 I drew nearer I had no doubt that here was one of the birds I 



