1902 Encyclopedia > Rhea

Rhea




RHEA, the name given in 1752 by Mohring to a South-American bird which, though long before known and described by the earlier writers—Nieremberg, Marcgrave, and Piso (the last of whom has a recognizable but rude figure of it)—had been without any distinctive scientific appellation. Adopted a few years later by Brisson, the name has since passed into general use, especially among English authors, for what their predecessors had called the American Ostrich; but on the European continent the bird is commonly called Jfandu, a word corrupted from a name it is said to have borne among the aborigina' inhabitants of Brazil, where the Portuguese settlers called it Ema (cf. EMEU, vol. viii. p. 171). The resemblance of the Rhea to the OSTRICH (vol. xviii. p. 62) was at once perceived, but the differences between them were scarcely less soon noticed, for some of them are very evident. The former, for instance, has three instead of two toes on each foot, it has no apparent tail nor the showy wing-plumes of the latter, and its head and neck are clothed with feathers, while internal distinctions of still deeper significance have since been dwelt upon by Prof. Huxley (Proc. Zool. Society, 1867, pp. 420-422) and the late Mr W. A. Forbes (op. cit., 1881, pp. 784-787), thus justifying the separation of these two forms more widely even than as Families; and there can be little doubt that they should be regarded as types of as many Orders—Struthiones and Rhex—of the Subclass Ratitx. Structural characters no less im-portant separate the Rheas from the Emeus, and, apart from their very different physiognomy, the former can be readily recognized by the rounded form of their contour-feathers, which want the hyporrhachis or after-shaft that in the Emeus and Cassowaries is so long as to equal the main shaft, and contributes to give these latter groups the appearance of being covered with shaggy hair. Though the Ehea is not decked with the graceful plumes which adorn the Ostrich, its feathers have yet a considerable market value, and for the purpose of trade in them it is annually killed by thousands, so that it has been already extirpated from much of the country it formerly inhabited, and its total extinction as a wild animal is probably only a question of time. Its breeding habits are precisely those which have been already described in the case of other Ratite birds. Like most of them it is polygamous, and the male performs the duty of incubation, brooding more than a score of eggs, the produce of several females—facts known to Nieremberg more than two hundred and fifty years since, but hardly accepted by naturalists until recently. From causes which, if explicable, do not here concern us, no examples of this bird seem to have been brought to Europe before the beginning of the present century, and accordingly the descriptions previously given of it by systematic writers were taken at second hand and were mostly defective if not misleading. In 1803 Latham issued a wretched figure of the species from a half-grown specimen in the Leverian Museum, and twenty years later said he had seen only one other, and that still younger, in Bullock's collection (Gen. Hist. Birds, viii. p. 379). A bird living in confinement at Strasburg in 1806 was, however, described and figured by Hammer in 1808 (Ann. du Museum, xii. pp. 427-433, pi. 39), and, though he does not expressly say so, we may infer from his account that it had been a captive for some years. In England the Report of the Zoological Society for 1833 announced the Ehea as having been exhibited for the first time in its gardens during the preceding twelvemonth. Since then many other living examples have been introduced, and it has bred both there and elsewhere in Britain, but the young do not seem to be very easily reared.





Though considerably smaller than the Ostrich, and, as before stated, wanting its fine plumes, the Ehea in general aspect far more resembles that bird than the other Ratitx. The feathers of the head and neck, except on the crown and nape, where they are dark brown, are dingy white, and those of the body ash-coloured tinged with brown, while on the breast they are brownish-black, and on the belly and thighs white. In the course of the memorable voyage of the "Beagle," Darwin came to hear of another kind of Rhea, called by his informants Avestruz petise, and at Port Desire on the east coast of Patagonia he obtained an example of it, the imperfect skin of which enabled Mr Gould to describe it (Proc. Zool. Society, 1837, p. 35) as a second species of the genus, naming it after its discoverer. Rhea darivini differs in several well-marked characters from the earlier known R. americana. Its bill is shorter than its head; its tarsi are reticulated instead of scutellated in front, with the upper part feathered instead of being bare; and the plumage of its body and wings is very different, each feather being tipped with a distinct whitish band, while that of the head and neck is greyish-brown. A further distinction is also asserted to be shewn by the eggs—those of R. americana being of a yellowish-white, while those of R. darwini have a bluish tinge. Some years afterwards Mr Sclater described (op. cit, 1860, p. 207) a third and smaller species, more closely resembling the R. americana, but having apparently a longer bill, whence he named it R. macrorhyncha, more slender tarsi, and shorter toes, while its general colour is very much darker, the body and wings being of a brownish-grey mixed with black. The precise geographical range of these three species is still undetermined. While R. americana is known to extend from Paraguay and southern Brazil through the state of La Plata to an uncertain distance in Batagonia, R. darwini seems to be the proper inhabitant of the country last named, though M. Claraz asserts (op. cit., 1885, p. 324) that it is occasion, ally found to the northward of the Bio Negro, which had formerly been regarded as its limit, and, moreover, that flocks of the two species commingled may be very frequently seen in the district between that river and the Eio Colorado. On the "pampas" R. americana is said to associate with herds of deer (Cariacus campestris), and R. darwini to be the constant companion of guanacos (Lama huanaeo)—just as in Africa the Ostrich seeks the society of zebras and antelopes. As for R. macrorhyncha, it was found by Forbes (Ibis, 1881, pp. 360, 361) to inhabit the dry and open "sertoes" of north-eastern Brazil, a discovery the more interesting since it was in that part of the country that Marcgrave and Piso became acquainted with a bird of this kind, though the existence of any species of Ehea in the district had been long overlooked by or unknown to succeeding travellers.

Besides the works above named and those of other recognized authorities on the ornithology of South America such as Azara, Prince Max of "Wied, Prof. Burmeister, and others, more or less valuable information on the subject is to be found in Darwin's Voyage ; Dr Booking's " Monographie des Nandu " in (Wiegmann's) Archiv fur Naturgeschichte (1863, i. pp. 213-241); Prof. E. O. Cunningham's Natural History of the Strait of Magellan and paper in the Zoological Society's Proceedings for 1871 (pp. 105-110), as well as Dr Gadow's still more important anatomical contributions in the same journal for 1885 (pp. 308 sq.). (A. N.)





Footnotes

3 Ann. Nat. History, ser. 4, xx. p. 500.

4 Mr Harting, in his and Mr De Mosenthal's Ostriches and Ostrich Farming, from which the woodcut here introduced is by permission copied, gives (pp. 67-72) some portentous statistics of the destruction of Rheas for the sake of their feathers, which, he says, are known in the trade as " Vautour " to distinguish them from those of the African bird.



The above article was written by: Prof. Alfred Newton.



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