Imitation. 1 79 



band, and not allowed to hear another bird, never learns 

 a perfect song, but sings a series of disconnected notes, 

 without any similitude to the parents' song. Young bull- 

 finches or greenfinches bred from the egg under canaries 

 learned their foster-parents' songs, and had none of the 

 harsh notes of their actual parents ; while young green- 

 finches taken from the nest when fledged, and then reared 

 by hand, always had some of their respective parents' 

 notes, although learning another song under a tutor. A 

 goldfinch-canary mule with a pure goldfinch song, when 

 two years old, learned the song of a linnet, and sang both 

 songs alternately and mixed. The time when the young 

 bird really picks up the song is in the nest, and before it 

 can feed itself. I have seen the featherless little birds 

 singing; that is, I have seen their throats going, and 

 heard their squeaky note, as though they were practising." 

 Mr. Hudson says* "that young oven-birds (Furnarius), 

 when only partially fledged, are constantly heard apparently 

 practising their duets in the intervals when the parents 

 are absent. On the hypothesis of tradition, it is just because 

 the young bird has predominant opportunities of hearing 

 its parents' notes that it sings the parent song. On the 

 other hand, Dr. A. G. Butler, f though he obtained evidence 

 of imitation in abundance, was led, from many observations, 

 to conclude that the tendency to imitate the song proper 

 to the species is stronger than the tendency to imitate 

 alien song, and that where foreign notes were caught up, 

 they were introduced into and added by the bird to its 

 own strains. I was assured many years ago by a bird- 

 fancier in London, that he had reared young nestlings, 

 such as thrushes and linnets, amid the strains of many 

 caged birds singing with varied power, and that the 



* " Naturalist in La Plata," p. 257. 

 t Zoologist, 1892, p. 30. 



