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Darwin Correspondence Project

To Philip Lutley Sclater   30 August [1870]1

Down. | Beckenham | Kent. S.E.

August 30th

My dear Mr Sclater,

I hope the Society will permit the enclosed note to be read & printed, as some palliation of my remarks on the woodpecker of the plains, versus Mr. Hudson.—2

Yours’ very sincerely | Ch. Darwin


In the last of Mr. Hudson’s valuable articles on the Ornithology of Buenos Ayres, he remarks, with respect to my observations on the Colaptes campestris, that it is not possible for a naturalist ‘to know much of a species from seeing perhaps one or two individuals in the course of a rapid ride across the Pampas.’3 My observations were made in Banda Oriental, on the northern bank of the Plata, where, thirty-seven years ago, this bird was common; and during my successive visits, especially near Maldonado, I repeatedly saw many specimens living on the open and undulating plains, at the distance of many miles from a tree.4 I was confirmed in my belief, that these birds do not frequent trees, by the beaks of some which I shot being muddy, by their tails being but little abraded, and by their alighting on posts or branches of trees (where such grew) horizontally and crosswise, in the manner of ordinary birds, though, as I have stated, they sometimes alighted vertically. When I wrote these notes, I knew nothing of the works of Azara,5 who lived for many years in Paraguay, and is generally esteemed as an accurate observer. Now Azara calls this bird the Woodpecker of the plains, and remarks that the name is highly appropriate; for, as he asserts, it never visits woods, or climbs up trees, or searches for insects under the bark.6 He describes its manner of feeding on the open ground, and of alighting, sometimes horizontally and sometimes vertically, on trunks, rocks, &c., exactly as I have done. He states that the legs are longer than those of other species of Woodpeckers. The beak, however, is not so straight and strong, nor the tail-feathers so stiff, as in the typical members of the group. Therefore this species appears to have been to a slight extent modified, in accordance with its less arboreal habits. Azara further states that it builds its nest in holes, excavated in old mud walls or in the banks of streams. I may add that the Colaptes pitius, which in Chile represents the Pampas species, likewise frequents dry stony hills, where only a few bushes or trees grow, and may be continually seen feeding on the ground. According to Molina, this Colaptes also builds its nest in holes in banks.7

Mr. Hudson, on the other hand, states that near Buenos Ayres, where there are some woods, the Colaptes campestris climbs trees and bores into the bark like other Woodpeckers. He says, ‘it is sometimes found several miles distant from any trees. This, however, is rare, and it is on such occasions always apparently on its way to some tree in the distance. It here builds its nest in holes in trees.’8 I have not the least doubt that Mr. Hudson’s account is perfectly accurate, and that I have committed an error in stating that this species never climbs trees.9 But is it not possible that this bird may have somewhat different habits in different districts, and that I may not be quite so inaccurate as Mr. Hudson supposes? I cannot doubt, from what I saw in Banda Oriental, that this species there habitually frequents the open plains, and lives exclusively on the food thus obtained. Still less can I doubt the account given by Azara of its general habits of life, and of its manner of nidification. Finally, I trust that Mr. Hudson is mistaken when he says that any one acquainted with the habits of this bird might be induced to believe that I ‘had purposely wrested the truth in order to prove’ my theory. He exonerates me from this charge; but I should be loath to think that there are many naturalists who, without any evidence, would accuse a fellow worker of telling a deliberate falsehood to prove his theory.


The year is established by the date the letters referred to in the enclosure were read (see n. 2, below).
Sclater was secretary of the Zoological Society of London. At the 24 February and 24 March 1870 meetings of the society, letters from William Henry Hudson were read in which Hudson claimed that CD was mistaken in his description of the pampas woodpecker, Colaptes campestris (now known as the Campo flicker), as a ‘woodpecker which never climbs a tree’ (Origin, p. 184; see Hudson 1870, p. 112, and also n. 4, below).
See Hudson 1870, p. 158.
For CD’s observations of woodpeckers in South America, see Zoology 3: 113–14, and Keynes ed. 2000, p. 156.
Félix d’Azara.
See Azara 1802–5, 2: 311–15.
Colaptes pitius is now known as the Chilean flicker. Juan Ignacio (Giovanni Ignazio) Molina described the nesting behaviour of the bird in Molina 1788–95, 1: 262. The passage is scored in CD’s copy of the book, which is in the Darwin Library–CUL (see Marginalia 1: 595).
Hudson 1870, p. 159.
CD added a reference to Hudson’s account in Origin 6th ed., p. 142.


Azara, Félix de. 1802–5. Apuntamientos para la historia natural de los páxaros del Paraguay y Rio de la Plata. 3 vols. Madrid: Impr. de la viuda de Ibarra.

Hudson, William Henry. 1870. On the ornithology of Buenos Ayres. [Letters from W. H. Hudson to the Zoological Society of London read 10 and 24 February, 24 March, 26 May, 23 June, 1 and 15 November, and 6 December 1870] Proceedings of the Zoological Society of London (1870): 87–9, 112–14, 158–60, 332–4, 545–50, 671–3, 748–50, 798–802.

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.

Molina, Juan Ignacio. 1788–95. Compendio de la historia geografica, natural y civil del reyno de Chile. Translated by Domingo Joseph de Arquella da Mendoza and Nicolas de la Cruz. 2 vols. Madrid: A. de Sancha.

Origin 6th ed.: The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 6th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1872.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

Zoology: The zoology of the voyage of HMS Beagle, under the command of Captain FitzRoy RN, during the years 1832 to 1836. Edited and superintended by Charles Darwin. 5 pts. London: Smith, Elder & Co. 1838–43.


Encloses, for publication, note about Pampas woodpecker, opposing W. H. Hudson [see 7354].

Letter details

Letter no.
Charles Robert Darwin
Philip Lutley Sclater
Sent from
Source of text
American Philosophical Society (Mss.B.D25.383)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 7311,” accessed on 11 April 2021,

Also published in The Correspondence of Charles Darwin, vol. 18