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Darwin Correspondence Project

From J. J. Weir   13 November 1873

6 Haddo Villas | Blackheath SE

13 Novr. 1873

My Dear Sir

I have hesitated some time before troubling you with a few notes I have made on hybridity this year, but at the risk of wearying you I have ventured to add another letter to the number already sent you.—1

Mr. Thomas Monk of Lewes had in his aviary a male Motacilla Boarula and a female Motacilla Yarrelii, and no others of the genus.—2

The two birds paired and in due time produced Hybrids, one only however survived, a male, till the next season, in the mean time the male Boarula died, the female Yarrellii then paired with her own male young one, and this year, there being still no others of the genus in the aviary, produced young twice, when I was at Lewes I saw the young in perfect health, being undoubtedly 3 parts Yarrellii and one part Boarula.—

When it is considered that the Wagtails are purely insectivorus birds & with difficulty kept in captivity, have so successfully been bred both as mules and as mule mules I consider the result as the greatest triumph of bird keeping I ever met with.—

The High Constables of Lewes have an ornamental piece of water, in which some ornamental waterfowl, are kept, last year there were two male Tufted Duck and a pair of Pochards, singularly the female Pochard left her mate and paired with one of the male Tufted Ducks the result last year was several Hybrids between the two species, which I saw and entertain no doubt of their Hybrid character, when at Lewes in the Spring I saw one of these hybrid Ducks sitting and it appeared she had paired with one of the Tufted Ducks, when I went again several young had been hatched, and this autumn I saw them again, & have not the slightest doubt that they are three parts Cristata and one part Ferina, and this was verified by Mr Verrall a resident Ornithologist who has closely watched them the whole season, so that here again I found an instance of a mule breeding, there were several broods produced besides, and one brood of seven, of which but one survived, Mr. Verrall tells me, he is nearly sure, were the produce of the mules Cristata-Ferina inter se.3

The third case I shall trouble you with is that of a hybrid between a common male fowl, Gallus domesticus, and a Duck Anas ferus, domesticated variety.4

There were some

CD annotations

1.1 I have … sent you.— 1.3] crossed pencil
5.1 The High … Ducks 5.4] ‘♀ Pochard left her mate & paired with ♂ Tufted Duck’ added pencil
6.1 The third … some 7.1] crossed pencil
Top of letter: ‘1 Duck deserting the other’ blue crayon, del pencil; ‘&’ blue crayon ‘Hybrids | *p. 2 ♀ deserting a male [del pencil] | J Jenner Weir’ pencil circled pencil


No other 1873 letters from Weir have been found, but see the letter to J. J. Weir, 22 May 1873.
Weir refers to Thomas James Monk. Motacilla boarula is the grey wagtail; Motacilla alba yarrellii is the pied wagtail.
In 1873, the High Constable of Lewes was Robert Crosskey (see Pall Mall Gazette, 20 October 1873, p. 6); Crosskey lived in the castle precinct (Census returns of England and Wales 1871 (The National Archives: Public Record Office RG10/1067/55/16)). The tufted duck was Fuligula cristata (now Aythya fuligula), and the common pochard is Aythya ferina. Weir refers to John Hubert Verrall.
The hybrid has not been identified. Gallus gallus domesticus is the common chicken; Anas ferus is a synonym of Anser anser, the wild goose (now usually referred to as the greylag goose). Anas ferus in Latin literally means ‘wild duck’, but the species name of the wild duck was Anas boschas, and is now Anas platyrhynchos.


Hybrid Motacilla.

Case of female duck leaving mate to pair with male of another species.

Letter details

Letter no.
John Jenner Weir
Charles Robert Darwin
Sent from
Source of text
DAR 88: 179–80
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9139,” accessed on 21 September 2020,

Also published in The Correspondence of Charles Darwin, vol. 21