This singular Neotropical form is even more isolated than the Flamingo and more difficult to place satisfactorily in a linear series. It seems, however, that it is best arranged near the Anatidæ, as first suggested by Mr. Parker[7], and that it may with least inconvenience be constituted an aberrant family of the Order Anseres.
Besides the typical form Palamedea (with one species found in Amazonia and the interior of Brazil) the present family contains only one other genus—Chauna—in which the head carries a feather-crest instead of the long horny wattle of Palamedea. One species of Chauna is met with in Argentina, the only other known species (C. derbiana) being confined to Colombia and Venezuela.
[7] Cf. Proc. Zool. Soc. 1863, p. 511.
[334.] CHAUNA CHAVARIA (Linn.).
(CRESTED SCREAMER.)
Palamedea chavaria, Burm. La-Plata Reise, ii. p. 506 (Paraná). Chauna chavaria, Scl. et Salv. Nomencl. p. 128; iid. P. Z. S. 1868, p. 145 (Buenos Ayres); Durnford, Ibis, 1878, p. 63 (Buenos Ayres); Gibson, Ibis, 1880, p. 165 (Buenos Ayres); Barrows, Auk, 1884, p. 272 (Entrerios).
Description.—Slaty grey, blacker on the back; chin, neck, and cheeks whitish; a naked ring round the neck; nape crested; belly whitish; feet red: whole length 32·0 inches, wing 19·0, tail 8·0. Female similar.
Hab. Southern Brazil, Paraguay, and La Plata.
This majestic bird, called Chajá in the vernacular, is common throughout the Plata district, in marshes and on the open level country abounding in water and succulent grasses, and ranges south to the neighbourhood of Bahia Blanca. It is most abundant on the pampas south of Buenos Ayres city, and on that vast expanse of perfectly level, green country the bird is seen at its best; it is there an important feature in the landscape; its vocal performances are doubly impressive on account of the profound silence of nature, and its singularity—the contrast between its aerial habit and ponderous structure—strikes one more forcibly where the view is so unobstructed and the atmosphere so pure.
The Crested Screamer, like most of the larger birds and mammals in every part of the globe to which European emigration is attracted, is probably doomed to rapid extermination. My observations of the bird, in that portion of the pampas where it is most abundant, date back some years, to a time when the inhabitants were few and mainly of Spanish race, never the destroyers of bird-life. The conditions had become extremely favourable to this species. It is partially aquatic in its habits; and in desert places is usually found in marshes, wading in the shallow water, and occasionally swimming to feed on the seeds and succulent leaves of water-loving plants. After the old giant grasses of the pampas had been eaten up by the cattle, and the sweet grasses of Europe had taken their place, the Screamers took kindly to that new food, preferring the clovers, and seemed as terrestrial in their feeding-habits as Upland Geese. Their food was abundant, and they were never persecuted by the natives. Their flesh is very dark, is coarse-grained but good to eat, with a flavour resembling that of wild duck, and there is a great deal of meat on a bird with a body larger than that of a Swan. Yet no person ever thought of killing or eating the Chajá; and the birds were permitted to increase to a marvellous extent. It was a common thing a few years ago in the dry season to see them congregated in thousands; and so little afraid of man were they that I have often ridden through large scattered flocks without making the birds take wing.