In April and May this Goose migrates northwards, along the eastern coast, as far as the pampas of Buenos Ayres, the migration ending about one hundred and fifty miles south of Buenos Ayres city. Further south they are at this season of the year excessively abundant in suitable localities. Their great camping-grounds are the valleys of the rivers Negro and Colorado, where they are often so numerous as to denude the low grounds of the tender winter clovers and grasses, and to cause serious loss to the sheep-breeders. They also visit the cultivated fields to devour the young wheat, and are intelligent enough to distinguish between a real human enemy and the ragged men of straw, miscalled scarecrows, set up by the farmers to frighten them. While committing their depredations they are exceedingly wary and difficult to shoot, but at night, when they congregate by the water-side, they give the sportsman a better chance. I have succeeded in killing as many as five at a shot by stalking them under cover of the darkness; and a more deliciously flavoured game-bird than this Goose I have never tasted. They are social birds, always going in large flocks, and are very loquacious, the female having a deep _honking_ note, while the male responds with a clear whistling, like the Sanderling's note etherialized. 337. BERNICLA POLIOCEPHALA, Gray. (ASHY-HEADED GOOSE.) +Bernicla poliocephala+, _Scl. et Salv. P. Z. S._ 1876, p. 366; _Burmeister, P. Z. S._ 1872, p. 366 (Bahia Blanca); _Scl. P. Z. S._ 1872, p. 549 (Rio Negro); _Durnford, Ibis_, 1878, p. 400 (Centr. Patagonia). +Chloephaga poliocephala+, _Scl. et Salv. Nomencl._ p. 128. _Description._--Head, neck, and scapulars greyish plumbeous; breast and upper back chestnut, banded across with black; abdomen, under wing-coverts, and bend of the wing white; primaries black; secondaries white; greater wing-coverts black, edged with shining green and tipped with white; lower back and tail black; flanks banded with white and black; crissum chestnut; bill black; feet on the outside yellow, on the inner side brownish black: whole length 24·0 inches, wing 13·5, tail 5·0. _Female_ similar. _Hab._ Patagonia, Southern Chili, and Southern Argentina. This Patagonian Goose migrates northwards in winter, and appears on the Rio Negro and in the Buenos-Ayrean pampas in May, usually in small flocks, but sometimes as many as one or two hundred are seen together. The extreme limit of their winter migration appears to be about sixty miles south of Buenos Ayres city, on the plains near the river Sanborombon; probably they have before now been driven from this locality by the Duck-shooters, but it was formerly their favourite rendezvous, where they collected in large numbers, though further north scarcely one was ever seen. Durnford tells us that this Goose is resident on Lake Colguape in the territory of Chupat, and breeds there abundantly.