208 EVOLUTION OF BIRD- SONG 



faculty, individuals seem to differ in ability, and I 

 have a note that, on 2ist March 1890, I listened 

 during seven minutes to two robins singing in a 

 thicket where willow -warblers are most abundant, 

 and I heard only one imitation of this bird's song ; 

 yet in summer I have heard it frequently mimicked 

 by robins at the same spot. On I5th February 

 1891, I heard at Grove House, Painswick, a robin 

 reproducing exactly the double alarm-cry, tewy chick, 

 of the redstart ; and I should have been deceived 

 had I not known that the redstart rarely utters this 

 cry except when the young are about, and so been 

 induced to look for the singer. I saw the robin 

 singing, but no redstart, nor have I ever seen one 

 of the latter in winter or before the end of March. 



MIMICRY OF THE SKYLARK 



The song of the skylark is equally interesting as 

 revealing a reproduction of cries of neighbouring 

 birds. Here is a summary of the principal imita- 

 tions sung by some thirty larks : 



Subject imitated. Skylarks. Times Exact 



reproduced, reproductions. 



Yellow Bunting's song 26 66 5 



Tree-pipit . . . 17 28 



Swallow 1 8 26 i 





