MUSICAL FEMALE BIRDS 289 



are not naturally mockers, but only develop the 

 imitative habit under human control and cultiva- 

 tion; for, as every one knows, Passerine birds, to 

 which all other talking and mocking species belong, 

 generally only sing when of the male sex. And 

 though to this there are numerous exceptions, of 

 which the hen of the beautiful Red Cardinal of 

 America {Cardinalis cardinalis) is perhaps the best 

 known, still there is no hen bird which sings better 

 than her mate, and none which sings while the 

 male is mute ; though, as we have seen in the case 

 of the Ducks, and as is also the case with the Guinea- 

 Fowl, the female may have a much stronger voice 

 than the male. In these cases, however, he is still 

 much- more loquacious than she is, and although his 

 voice to us sounds weaker, her ear may be more 

 attuned to it. 



There are some curious cases of coincidental 

 resemblances between voices of unrelated birds 

 and between sounds made by birds and by mammals 

 and even produced by mechanical means, which 

 deserve attention. Many people must have noticed 

 the great resemblance between the piping call of 

 the Kingfisher and that of the common Sandpiper, 

 and between the note of the Kestrel and that of 

 the Wryneck. I have noted others in cases where 

 the birds do not occupy the same country, at any 

 rate when breeding ; thus the pretty Wire-tailed 

 Swallow (Hirundo smithii) of Africa and India, has 

 exactly the same call-note " swee-et " as the Canary, 

 an Azorean species ; and an Australian Dove 



^9 



