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Darwin Correspondence Project

From J. J. Weir   7 March 1868

6 Haddo Villas | Blackheath SE

7 M’ch 1868

My Dear Sir

I hasten to apologize for having written genus “Edusa”, it was a lapsus calami   I intended “Colias” but having the common species in my mind I made the error.—1

If Edusa is seen to settle unless you mark the spot very carefully it is difficult to find, so well do its colors harmonize with the vegetation it frequents.—2

I know you like as many facts bearing on a case as possible & therefore venture to add a few similar to those already known.

My friend Mr. F Bond shot a Corvus corone from the nest & took out four eggs, a fortnight afterwards, he again shot from the same nest another bird, again he took out 4 eggs.—3

I knew of a case of a kestrels nest from which three males in succession were shot, the two first in the mature plumage with the blue tail, the last in the immature plumage of the young male of the previous year.—4

Last year a Gamekeeper of a friend of mine at Brenchley killed both male & female from a nest & took out all the young ones which were nailed up in the usual manner,5 but in the Autumn the kestrels were there still & from the screams they made when I went near the spot it appeared to me that young had been reared after all.—

I do not however give this last case as more than a corroborative one.—

You have probably observed in Pigeons that when the male or female are sitting, the bird off the nest leads an unchaste life.—

This I feel convinced occurs in nature, but as wild birds almost always resemble each other the bastardy is rarely noticed.

I have met with a case in which a Goldfinch and a Greenfinch built a nest each in the same tree, but one of the young birds in the Goldfinch’s nest was a hybrid between the two species, I have seen several other hybrids probably so produced in nature between the species adverted to, and between the Green & Gray linnet, the Chaffinch & Bramblefinch once, and was just too late yesterday to see one between the Gray & the Mountain Linnet.—6

I do not think it is quite clear that all birds are paired even if the nest contains young

I caught a hen sparrow last year and cut off her tail, for hours I watched that bird, she had a nest & reared her young but not once did I see a male either with her or feeding the young, but of course I do not suppose it was a case of parthenogenesis.—

On the other hand my friend Newman (a sad Antidarwinian) tells me that three Starlings were associated with one nest in his house at Peckham.—7

Again an observing friend of mine saw at Buenos Ayres, three Parots engaged in building one nest.—8

It is quite certain in captivity that Canaries become polygamous, & I think pantagamous, Four males in a room is the usual allowance for twelve females.—9

There is another curious fact, two female pigeons will sometimes appear to pair, I have known 4 eggs produced under such circumstances.—

I think you may safely rely on the fact that the beak of the male Goldfinch is longer than the female, it is the mode in which the sexes are separated by Dealers before the change from the nestling plumage.10

I have a few remarks on birds not eating brightly colored catterpillars which I will reserve for my next

Yours very sincerely | J Jenner Weir

C Darwin Esqr.

CD annotations

1.1 I hasten … already known. 3.2] crossed pencil
2.1 Edusa] ‘The clouded yellow’ added pencil
4.1 My friend … after all.— 6.4] crossed ink
13.1 On … one nest.— 14.2] crossed blue crayon
16.1 There is … my next 18.2] crossed pencil
Top of letter: ‘BB’ blue crayon circled blue crayon, over ‘B’ red crayon; ‘Polygamy’ pencil circled pencil


Frederick Bond stuffed birds he had shot and collected eggs (Salmon 2000, p. 156). Corvus corone is the carrion crow.
The tail of a male Falco tinnunculus (kestrel) does not get its blue coloration until the second year. For more on moulting patterns in kestrels, see Village 1990, pp. 88–97. CD referred to Weir’s case in Descent 2: 104–5.
Weir’s friend in Brenchley, a village near Tunbridge Wells in Kent, has not been identified. Weir refers to the practice of nailing up vermin as a deterrent to others.
Weir refers to Carduelis elegans (the goldfinch, now C. carduelis), Carduelis chloris (the greenfinch), Linaria cannabina (the common (grey) linnet, now Carduelis cannabina), Fringilla coelebs (the chaffinch), Fringilla montifringilla (the brambling or bramble finch), and Linaria montana (the mountain linnet or twite, now Carduelis flavirostris). Green linnet is a local name for the greenfinch (Greenoak 1997, p. 203). In Descent 2: 113, CD mentioned Weir’s belief that hybrids sometimes occurred when related species nested near each other.
Edward Newman lived at 7 York Grove, Peckham, Surrey (Post Office directory of the six home counties 1866). In Descent 1: 269, CD noted Weir’s information on three starlings nesting together. On starling nesting behaviour, see Feare 1984, pp. 118–23.
Weir’s friend has not been identified. One parrot species native to Buenos Aires builds communal nests, Myiopsitta monachus (the monk parakeet or Quaker parrot; see Juniper and Parr 1998, p. 475). In Descent 2: 107 n. 7, CD acknowledged Weir’s information on starlings and parrots.
The canary is Serinus canaria. In Descent 1: 270, CD mentioned polygamy in canaries, but did not cite Weir for the information.


Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.

Feare, Christopher. 1984. The starling. Oxford: Oxford University Press.

Greenoak, Francesca. 1997. British birds: their folklore, names and literature. London: Christopher Helm.

Post Office directory of the six home counties: Post Office directory of the six home counties, viz., Essex, Herts, Kent, Middlesex, Surrey and Sussex. London: W. Kelly & Co. 1845–78.

Salmon, Michael A. 2000. The Aurelian legacy: British butterflies and their collectors. With additional material by Peter Marren and Basil Harley. Colchester: Harley Books.

Village, Andrew. 1990. The kestrel. London: Poyser.


Various facts about birds: pairing, finding new mates, protective coloration, polygamy, sexual differences.

Letter details

Letter no.
John Jenner Weir
Charles Robert Darwin
Sent from
Source of text
DAR 86: A21–4
Physical description
8pp †

Please cite as

Darwin Correspondence Project, “Letter no. 5995,” accessed on 1 December 2021,

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