The imitative 'power of birds. 327


THE IMITATIVE POWER OF BIRDS.


By Dr. A. G. Butler.


In an article on Bird Song in the September No. of our

Magazine “Birdlover” asks—“does each species possess a definite

congenital song?” and he comes to the conclusion that it does,

because if not “ What is there to prevent the young from assimila¬

ting the notes of the more vociferous individuals of other species in

the vicinity of their nest, if song is an individual acquirement, a

mere matter of imitation.” If our friend had read a very careful

treatise by the late Charles A. Witchellentitled “ The evolution of

Bird-song with observations on the influence of heredity and imita¬

tion” he would have been aware that this is exactly what frequently

happens in the case of wild birds.


Undoubtedly the song of many species appears to be heredi¬

tary, though in the case of the best singers the performance of two

individuals of the same species, while similar in character, is utterly

dissimilar in detail. Two Song-thrushes may have certain phrases

in common, but their songs as a whole always differ, and so it is

with several of the best singers : moreover many of them introduce

into their music parts of the songs of other birds. It is not only

the Mocking-birds of the New World which delight our ears with a

combination of the melodies of other and varied performers ; I have

heard our Song'thrush and Blackbird, when singing against a Night¬

ingale in a Kentish plantation, steal many of his phrases to improve

their own songs.


As a general rule a young bird in the nest hears its father’s

(or its mother’s song, for many hen birds singt) performance far

more frequently than that of other species, and consequently its own

song is likely to be similar in character ; but that this is not in¬

variably the case is certain from the fact which I recorded (British

Birds with their nests and eggs, Yol. I., p. 119) of a cock Sedge-

Warbler singing the song of a Blackcap. The late Mr. Edward A.

Fitch, of Maldon in Essex, who was with me insisted that the nest


* Published in 1896 by Adam and Charles Black:


t A hen robin which followed me about my garden, whenever it saw me weeding

this year, sang repeatedly, rather to my surprise as I had never heard a hen

robin sing before.



