(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.