From H. B. Tristram 5 September 1868
Greatham Vicarage Stockton on Tees
5 Sept. 1868.
My dear Sir
In Monticola cyanea the ♀ is less brightly coloured than the ♂ but not so as to render her less conspicuous, being a very dark mottled brown with some white.1 The ♀s of the Indian, Chinese, Phillipini, & So. African species differ similarly, & there is no exception in this genus.2 The question as to the Dromolæa leucopygia, & D. leucocephala is very curious, because in these species, as in Saxicola leucomela, there is no difference whatever in the sexual coloration.3 While there are species very slightly from these 3 respectively e.g. Drom. monacha, & Saxicola libanotica, where the female is a pale sandy colour, most inconspicuous,4 yet all inhabit the same localities, have precisely the same nidification, & the eggs are so alike, that only careful observation of the parent bird could decide to what species they belong. Yet the notes & flight of all the species are so distinct, it is impossible to confound the birds even at a distance.
I find a similar parallelism & contrast in the South African & Himalayan species.
Should you wish to examine for yourself, I shall be very happy to forward you a box of specimens of the various species carefully marked in pairs.
There is nothing more apparently capricious than the colouring of the ♀ in the Chat family,5 now identical, now most different in the closest allies— The contrast of blackbird & thrush in this respect is analogous—
Believe me | My dear Sir | Yrs very truly | H. B. Tristram
CD annotations
Footnotes
Bibliography
Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.
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.
Tristram, Henry Baker. 1859–60. On the ornithology of northern Africa. Ibis 1: 153–62, 277–301, 415–35; 2: 68–83.
Summary
Sexual differences in plumage of birds; various species compared.
Letter details
- Letter no.
- DCP-LETT-6351
- From
- Henry Baker Tristram
- To
- Charles Robert Darwin
- Sent from
- Stockton-on-Tees
- Source of text
- DAR 84.1: 95–6
- Physical description
- ALS 4pp †
Please cite as
Darwin Correspondence Project, “Letter no. 6351,” accessed on 4 October 2023, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-6351.xml
Also published in The Correspondence of Charles Darwin, vol. 16