(WHITE-FACED IBIS.)
+Plegadis guarauna+, _Baird, Brew., et Ridgw. Water-B. N. A._ i. p.
97. +Falcinellus guarauna+, _Elliot, P. Z. S._ 1877, p. 505.
+Ibis falcinellus+, _Hudson, P. Z. S._ 1870, p. 799 (Buenos
Ayres). +Falcinellus igneus+, _Durnford, Ibis_, 1877, p. 189
(Buenos Ayres). +Plegadis falcinellus+, _Gibson, Ibis_, 1880, p.
155 (Buenos Ayres); _Barrows, Auk_, 1884, p. 272 (Entrerios).
+Ibis chalcoptera+, _Burm. La-Plata Reise_, ii. p. 511 (Paraná,
Mendoza).
_Description._--Head, neck, and under surface purplish chestnut,
with a white band round the base of the bill; back with metallic
reflexions; wings and tail bright green, with bronzy reflexions;
band across upper wing-coverts chestnut; bill reddish grey; feet
brown: whole length 22·0 inches, wing 9·0, tail 3·0. _Female_
similar.
_Hab._ Central and South America.
This form of the well-known "Glossy Ibis" of Europe is one of our most
abundant waterfowl on the pampas, and appears in spring in flocks; but
as their movements are somewhat irregular and many individuals remain
with us through the winter, their migrations probably do not extend
very far. In summer they are found beside every marsh and watercourse,
briskly wading about in the shallow water and plunging their long curved
beaks downwards at every step. When taking wing they invariably utter a
loud _ha ha ha_, resembling hearty human laughter, but somewhat nasal in
sound. They frequently leave the marshy places and are seen scattered
about the grassy plains, feeding like land-birds; and on the pampas they
often congregate about the carcass of a dead horse or cow, to feed on
the larvæ of the flesh-fly in company with the Milvago and the Hooded
Gull.
Their flight is singularly graceful; and during migration the flocks are
seen to follow each other in rapid succession, each flock being usually
composed of from fifty to a hundred individuals, sometimes of a much
larger number. It is most interesting to watch them at such times, now
soaring high in the air, displaying the deep chestnut hue of their
breasts, then descending with a graceful curve towards the earth, as if
to exhibit the dark metallic green and purple reflexions of their
upper plumage. The flock is meanwhile continually changing its form or
disposition, as if at the signal of a leader. One moment it spreads out
in a long straight line; suddenly the birds scatter in disorder, or
throw themselves together like a cloud of Starlings; as suddenly they
again reform to continue their journey in the figure of a phalanx,
half-moon, or triangle. The fanciful notion can scarcely fail to suggest
itself to the spectator that the birds go through these unnecessary
evolutions intelligently in order to attain a greater proficiency in
them by practice, or, perhaps, merely to make a display of their aerial
accomplishments. The Glossy Ibis has another remarkable habit when
on the wing. At times the flock appears as if suddenly seized with
frenzy or panic, every bird rushing wildly away from its fellows, and
descending with a violent zigzag flight; in a few moments the mad fit
leaves them, they rise again, reassemble in the air, and resume their
journey.