(BLACK-FACED IBIS.)
+Theristicus melanops+, _Darwin, Zool. Beagle_, iii. p. 128
(Patagonia). +Geronticus melanopis+, _Scl. P. Z. S._ 1871, p.
261. +Theristicus melanopis+, _Scl. et Salv. Nomencl._ p. 127;
_Durnford, Ibis_, 1877, p. 190 (Buenos Ayres), et 1878, p. 400
(Patagonia); _Barrows, Auk_, 1884, p. 272 (Azul). +Theristicus
caudatus+, _Elliot, P. Z. S._ 1877, p. 498. +Ibis albicollis+,
_Burm. La-Plata Reise_, ii. p. 510 (Paraná, Mendoza, Tucuman).
_Description._--Sides of throat, and lores bare, skin black; top of
head and lower part of neck in front reddish chestnut; neck white, a
narrow line of feathers running up the centre of the throat to the
chin; back and wings greyish brown, with green reflexions, feathers
edged with light brown or whitish; tertials and outer webs of
secondaries for two thirds of their length white, remainder dark
green; primaries dark green; rump and upper tail-coverts light
bronzy green; tail dark bronze-green; underparts brownish black,
with green reflexions: whole length 33·0 inches, wing 16·25, tail
9·75, bill along culmen 7·0, tarsus 3·5. _Female_ similar.
_Hab._ Antarctic South America.
This very fine Ibis, called _Mandurria ó curucáu_ by Azara and _Vanduria
de Invierno_ (winter Vanduria) in the vernacular, is one of the most
interesting winter visitors from Patagonia to the pampas of Buenos
Ayres. It is found in Chili, and has even been obtained as far north as
Peru. On the east side of the continent it is most abundant (during
the cold season) about latitude 37° or 38°. Its summer home and
breeding-ground appears to be in the extreme south of the continent,
its eggs having been obtained in the Straits of Magellan by Darwin, and
recently by Dr. Cunningham, who only says of it that it is a shy and
wary bird, that goes in flocks of from four to eight, and has a cry
resembling _qua-qua, qua-qua_. But he might just as well have spelt it
_quack-quack_, since _qua-qua_ fails to give the faintest idea of the
series of hard abrupt notes of extraordinary power the bird utters,
usually when on the wing, which sound like blows of a powerful hammer
on a metal plate. On the pampas this Ibis appears in May, frequents
dry grassy situations, and goes in flocks of a dozen to forty or fifty
individuals. They walk rapidly, stooping very much, and probing the
ground with their long slender curved beaks, and appear to subsist
principally on the larvæ of the large, horned beetle, with which their
stomachs are usually found filled. So intent are they on seeking their
food that the members of a flock often scatter in all directions
and wander quite out of sight of each other; when this happens they
occasionally utter loud vehement cries, as if to call their companions,
or to inform each other of their whereabouts. Frequently one is seen to
lift up its wings as if to fly, and, stretching them up vertically, to
remain for fifteen or twenty seconds in this curious attitude. At sunset
they all rise up clamouring, and direct their flight to the nearest
watercourse, and often on their way thither go through a strange
and interesting performance. The flock suddenly precipitates itself
downwards with a violence wonderful to see, each bird rushing this way
and that as if striving to outvie its fellows in every wild fantastic
motion of which they are capable. In this manner they rise and descend
again and again, sometimes massed together, then scattered wide apart
in all directions. This exercise they keep up for some time, and while
it lasts they make the air resound for miles around with their loud
percussive screams.
In Patagonia I first observed this Ibis roosting on tall trees; and,
according to Azara, it possesses the same habit in Paraguay. He says
that all the flocks within a circuit of some leagues resort to one spot
to sleep, and prefer tall dead trees bordering on the water, and if
there is only one suitable tree all the birds crowd on to it, and in the
morning scatter, each family or pair flying away to spend the day in its
customary feeding-ground.
The egg obtained by Dr. Cunningham at Elizabeth Island is thus described
by Prof. Newton (Ibis, 1870, p. 502)[5]:--"Dull surface of a pale
greenish white with engrained blotches (mostly small) of neutral tint,
and some few blotches, spots, and specks of dull deep brown; towards the
larger end some hair-like streaks of a lighter shade of the same, and so
far having an Ibidine or Plataleine character."
[5] See also figure, P. Z. S. 1871, pl. iv. fig. 8.