U4 EVOLUTION OF BIRD-SONG 



Howard Saunders places the species in close 

 alliance ; and the late Dr. Bree wrote that the call- 

 note of the marsh- warbler (Sylvia palustris] is 

 similar to that of other reed -warblers (Birds of 

 Europe, vol. ii. p. 73). 



In regard to voice I should place the hedge- 

 sparrow near the robin, because the call-squeak of 

 the former is like that of the latter. 



It might be well in this place to recapitulate in 

 a concise way the cries connecting the various 

 forms already mentioned. In the Corvidce the 

 croak of the raven is changed to a loud corrr in the 

 crow, caw in the rook, cah in the jay, and a modified 

 cry uttered as an alarm by the starling. The 

 jackdaw utters it as a vehement alarm. The 

 starling's notes of passionate song are high toneless 

 squeals uttered at the end of the phrase, and often 

 accompanied by a flapping of the wings. These 

 notes separate this bird from the crows to which it 

 is related by its alarm and the cries of its young. 

 They form a link with the thrushes. The rattling 

 screech of the mistle-thrush is uttered by its young, 

 and is modified progressively in the common thrush, 

 ring-ouzel, fieldfare, American robin, and blackbird, 

 and seemingly in the South African olivaceous 

 thrush. The robin's rattled cry has points of re- 



