+Dendrocygna fulva+, _Burm. La-Plata Reise_, ii. p. 514 (Paraná); _id. P. Z. S._ 1872, p. 367; _Scl. et. Salv. Nomencl._ p. 129; _iid. P. Z. S._ 1869, p. 635 (Buenos Ayres), et 1876, p. 372; _Durnford, Ibis_, 1878, p. 63 (Buenos Ayres); _White, P. Z. S._ 1882, p. 625 (Buenos Ayres). _Description._--Chestnut-red, top of head darker, with black line down the nape; back black, on the upper portion banded with chestnut; wings and tail black; lesser wing-coverts dark chestnut; upper tail-coverts white; flank-plumes elongated, chestnut, banded with black and white; bill and feet black: whole length 18·0 inches, wing 8·5, tail 2·0. _Female_ similar. _Hab._ Mexico and South America. This Duck, the well-known _Pato silvon_ (Whistling Duck) of the eastern Argentine country, is found abundantly along the Plata and the great streams flowing into it, and northwards to Paraguay. Along this great waterway it is to some extent a migratory species, appearing in spring in Buenos Ayres in very large numbers, to breed in the littoral marshes and also on the pampas. They migrate principally by night, and do not fly in long trains and phalanxes like other Ducks, but in a cloud; and when they migrate in spring and autumn the shrill confused clangour of their many voices is heard from the darkness overhead by dwellers in the Argentine capital; for the Ducks, following the eastern shore of the sea-like river, pass over that city on their journey. Northwards this Duck extends to Central Brazil; from the northern half of the southern continent and from Central America it is absent, but it reappears in Mexico. Commenting on these facts Messrs. Sclater and Salvin write:--"Singular as this distribution is, it is still more remarkable when we consider that there appear to exist no tangible grounds for separating the American bird from that called _D. major_ by Jerdon, which ranges throughout the peninsula of India and is also found in Madagascar!" The Whistling Duck, in its chestnut and fulvous plumage, is a handsome bird and somewhat singular in appearance, especially when seen in a large body on the ground. When out of the water they crowd close together, and when disturbed stand up craning their necks, looking strangely tall on their long blue legs. While thus watching an intruder they are silent, and the sudden ringing chorus of whistling voices into which they burst at the moment of rising has a curious effect.