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Darwin Correspondence Project

From J. J. Weir   18 May 1868

6 Haddo Villas | Blackheath SE

18 May 1868

My Dear Sir

I will endeavour to reply to some of your questions1

1 Does any ♀ bird regularly sing?

The bird catchers say they cannot distinguish between a ♂ & ♀ Robin2 in the Autumn   All Robins then appear to sing the Autumnal note, which is however different from the song of Spring.—

My own observations would I think support this view, but on the other hand I had one Robin in captivity which did not sing.—

The ♀ Bullfinch is reputed to sing although not so well as the male, the black Bullfinch so often adverted to3 was continuously singing when I purchased her, & caused me to think she was a ♂, but she is undoubtedly a ♀, and very salacious, I have seen her receive a male Reed Bunting as well as her own species, & I am inclined to think such accidental impregnations are the cause of hybrids so often appearing among finches.—

The numerous German Canaries so much sold in our streets are mostly hens, they certainly sing after a fashion, yet sufficiently well for many persons to prefer them to the shriller notes of the ♂.—4

Reply to second query

I know of no case of any bird either ♂ or ♀ becoming duller when adult

I am however inclined to think that very old Linnets Redpolls and Crossbills cease to have the red in their plumage, I have seen wild linnets with yellow breasts in the breeding season and wild Linota Canescens with yellow crowns.—5

Reply to query 3.—

There is a very marked difference between the ♂ & ♀ wild canary, the colors are similarly disposed but in the male they are far brighter.—

This is lost in the domesticated bird even the “green birds” have the males scarcely brighter than the hens.—6

I know of no gallinaceous bird in which the hen has spurs, it might be expected in the genus Polyprectron, but the references I have made speak of the hen as spurless.—7

I do not know whether the “spurs” on the wings of Chauna and Parra are sexual.—8

The wings of the Turkey are ornamented but these are continuously displayed when courting, this is not the case with the common fowl Gallus nor do I think it is with G. Bankiva,9 but you must remember that the wing is expanded but for a moment & that on the side opposite to the hen,

CD annotations

1.1 I will … query 3.— 10.1] crossed pencil
7.1 Reply to second query] ‘18 May’ added blue crayon
8.1 I know … adult.] scored blue crayon
11.1 There is] after opening square bracket blue crayon
13.1 I know … sexual.— 14.2] crossed blue crayon
15.1 The … the hen, 15.4] crossed pencil
End of letter: ‘it appears to be done to assist the bird with semi-gyration by the side of the ♀’ ink


The European robin, Erithacus rubecula.
Canaries (Serinus canaria) bred in Germany as songbirds were imported annually by dealers (see R. L. Wallace [1889], p. 259; see also Newton 1893–6, 1: 70–2).
Linota canescens: the mealy or common redpoll, now Carduelis flammea.
Green canaries were obtained in the canary trade from cross-breeding different varieties (see R. L. Wallace [1889], pp. 257–9). Green is the natural colour of wild ancestor of domestic canaries (Serinus canaria).
Polyplectron, the peacock-pheasant genus.
Chauna: screamers. Parra: jacanas. Jacanas are now distributed among a number of different genera. See also Correspondence vol. 15, letter from Edward Blyth, 19 February 1867, n. 30.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Newton, Alfred. 1893–6. A dictionary of birds. Assisted by Hans Gadow, with contributions from Richard Lydekker, Charles S. Roy, and Robert W. Shufeldt. 4 parts. London: Adam and Charles Black.

Wallace, Robert L. [1889.] The canary book. 2d edition. London: L. Upcott Gill.


Answers CD’s question on whether any female birds regularly sing.

Letter details

Letter no.
John Jenner Weir
Charles Robert Darwin
Sent from
Source of text
DAR 84.1: 81–2, DAR 86: A37–8
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 6181,” accessed on 19 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 16