(WHISTLING THORN-BIRD.)
+Phacellodomus sibilatrix+, _Scl. P. Z. S._ 1879, p. 461; _White, P.
Z. S._ 1882, p. 612 (Buenos Ayres); _Barrows, Bull. Nutt. Orn.
Cl._ viii. p. 209 (Entrerios).
_Description._--Above dull olive-brown, paler on the sides of the
head; front and lesser wing-coverts chestnut-red; wing-feathers
blackish, edged with olive-brown; tail light chestnut, the middle
pair of feathers and the inner webs of the two next pairs brown,
like the back; beneath dirty brownish white, washed with ochraceous
on the flanks; under wing-coverts bright cinnamon: whole length 5·3
inches, wing 2·2, tail 2·2.
_Hab._ Argentina.
This species resembles _P. frontalis_, but differs in its much smaller
size, and in having the upper lesser wing-coverts bright rufous.
It inhabits the thorny woods of the northern districts of the Argentine
country, but I have no reason to regret that I have not personally
observed this species, since Mr. Barrows's careful account of
its nesting-habits leaves nothing to be desired. He writes:--"An
abundant species among the open woods along the Uruguay, and hardly
distinguishable at ten paces from half a dozen others. Its nest,
however, is unmistakable. The birds begin by fixing a few crooked and
thorny twigs among the terminal sprays of some slender branch which juts
out horizontally from a tree, or rises obliquely from near its base, and
around these twigs as a nucleus more are gathered, until, by the time
the nest has reached the proper size, its weight has bent the branch so
that its tip points directly to the earth. Nests which are thus begun at
a distance of fifteen or twenty feet from the ground are often only two
or three feet from it when finished, and a thorough soaking by a heavy
rain will sometimes weigh them down until they actually touch. They are
more or less oval or cylindrical in shape, and commonly about two feet
long by twelve or fifteen inches in diameter, and contain from a peck
to a bushel of twigs and thorns. The nest-cavity within is small in
proportion to the size of the nest, and occupies its upper part. It is
reached by a more or less direct passage-way from below, the external
opening being very nearly at the lowest part of the nest, though
sometimes a little shelf, or even a pocket, is built on to the side,
forming a resting-place in front of the door.
"The nests vary interminably in size and shape, but are pretty constant
in the material used; this being almost always irregular and thorny
twigs of various trees growing in the neighbourhood, while the interior
is formed of less thorny twigs and with some wool and hair. Usually,
also, if the material be at hand, a quantity of old dry horse-droppings
is placed loosely on the top of the nest, and gradually becomes felted
into it, rendering it more nearly waterproof. In place of this I have
frequently found quantities of broken straw, weed-stalks, grass, and
even chips; all doubtless collected from the ridges of drift which the
last overflow of the river had left near at hand. So compactly is the
whole nest built, that it often lasts more than one year, and may
sometimes serve the same pair two successive summers. More often,
however, a new nest is built directly above the old one, which serves
as a foundation, and occasionally as many as three nests are seen thus
on the same branch-tip, two of them at least being occupied. When other
branches of the same tree are similarly loaded, and other trees close at
hand also bear the same kind of fruit, the result is very picturesque.
The eggs, which are white, are laid from October 1 to January 1, but
many of the birds work at nest-building all the winter, sometimes
spending months on a single nest."