NOTES AND QUERIES. 303 



parts closely resembled a common Short-tailed Field Vole. The length of 

 its tail, its prominent ears, white under parts, and above all the characters 

 of its grinding teeth, were, however, sufficient to establish its identity. — 

 Charles Oldham (Romiley). 



[The Bank Vole being absent from Ireland, it is extremely interesting 

 to have thus established the precise limit of its range westward. — Ed.] 



BIRDS. 



The Imitative Faculty in Birds, — Last November a live Tree 

 Sparrow, Passer montanus, was brought to me which had been taken in 

 one of the "clap-nets" so lamentably common and so destructive in this 

 locality during the winter. It has been kept in a cage in proximity to a 

 hybrid Canary and Goldfinch, and since April (up to which time it appeared 

 to be vocally silent) I have often remarked the accuracy with which it 

 reproduces the notes — and, more rarely, a longer or shorter fragment of 

 the song — of its companion. Its own song possesses qualities distinctly 

 pleasing but scarcely comparable to the brilliant effervescence it counterfeits 

 in the more gifted hybrid, Latterly the imitations have been more varied 

 and skilful than were the first attempts ; and this is certainly a note- 

 worthy feature, indicating as it does that the mimical faculty is capable 

 of considerable development. Montagu mentioned (Orn. Diet. 1802, art. 

 " Song of Birds") — and, indeed, Aristotle speculated in effect on the same 

 subject long before — that birds when confined learn the songs of those they 

 most frequently hear; but, as is now well known, many species in the 

 reverse condition are given to mimicking their fellows. As an instance of 

 the latter case I may mention that my father, Mr. E. P. P. Butterfield, has 

 recorded (Zool. 1877, p. 384) his having heard a Whinchat, a bird of no 

 extensive vocal capability, imitate " in quick succession the song of the 

 Wren, Song Thrush, Chaffinch, Corn Bunting, Tree Pipit, Greenfinch, and 

 Starling." Similar instances will occur to all who have any experience of 

 field ornithology — it is notorious that the faculty obtains amongst members 

 of the genus Acrocephalus. I cannot wholly agree with the writer of an 

 ingenious theory in 'The Zoologist' (1890, p. 233 et seq.) who supposes 

 birds' songs to have originated in the imitation of constantly recurring 

 sounds connected with their food or surroundings. If the song of a species 

 varies dialectically in different areas of its geographical range — and that 

 such is the case would appear to be well established — there can be no 

 reason biologically why the different "dialects" may not ultimately depart 

 as variantly from what may be considered the typical specific song as do 

 the songs of allied species. In our present state of knowledge it behoves 

 us to hazard a conjecture regarding the origin of song with the utmost 

 caution. For myself I incline to think that Mr. Darwin was right in 

 giving prominence to sexual selection as accounting both for the origin 



