(DUSKY THRUSH.)
+Turdus leucomelas+, _Scl. et Salv. Nomencl._ p. 1; _Hudson, P. Z.
S._ 1870, p. 798 (Buenos Ayres); _Durnford, Ibis_, 1877, p. 166
(Buenos Ayres); _White, P. Z. S._ 1882, p. 592 (Misiones and
Corrientes); _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 85
(Concepcion); _Seebohm, Cat. Birds_, v. p. 213. +Turdus
crotopezus+, _Burm. La-Plata Reise_, ii. p. 474 (Mendoza).
_Description._--Above olive-grey, tinged with brown on the head and
neck; beneath pale grey, throat white, more or less striped with
brown; middle of belly and crissum white; under wing-coverts and
inner margins of wing-feathers fulvous; bill yellow; feet hazel:
total length 9·0 inches, wing 4·5, tail 3·7. _Female_ similar.
_Hab._ Eastern South America, from Cayenne to Buenos Ayres.
The Dusky Thrush is widely distributed in South America, and ranges as
far south as Buenos Ayres, where it is quite common in the woods along
the Plata river. It is a shy forest-bird; a fruit- and insect-eater;
abrupt in its motions; runs rapidly on the ground with beak elevated,
and at intervals pauses and shakes its tail; pugnacious in temper;
strong on the wing, its flight not being over the trees, but masked
by their shadows. It can always be easily distinguished, even at a
distance, from other species by its peculiar short, metallic chirp--a
melodious sound indicating alarm or curiosity, and uttered before
flight--in contrast to the harsh screams and chuckling notes of other
Thrushes in this district.
Whether it is a fine singer or not within the tropics I am unable to
say, its vocal powers having received no attention from the naturalists
who have observed it. With us in the temperate climate of Buenos Ayres,
where it commences to sing in September, it has the finest song of
any bird I know, excepting only _Mimus triurus_. Like the English
Song-Thrush, but unlike its near neighbours the Red-bellied Thrush and
the Magellanic Thrush, it perches on the summit of a tree to sing. Its
song is, however, utterly unlike that of the English bird, which is
so fragmentary, and, as Mr. Barrows describes it, made up of "vocal
attitudes and poses." The two birds differ also in voice as much as in
manner. The strains of the Dusky Thrush are poured forth in a continuous
stream, with all the hurry and freedom of the Sky-Lark's song; but
though so rapidly uttered, every note is distinct and clear, and the
voice singularly sweet and far-reaching. At intervals in the song there
recurs a two-syllabled note twice repeated, unlike in sound any other
bird-music I have heard, for it is purely metallic, and its joyous
bell-like "_te-ling te-ling_" always comes like a delightful surprise
to the listener, being in strange contrast with the prevailing tone.
The song is altogether a very fine one, its peculiar charm being that it
seems to combine two opposite qualities of bird-music, plaintiveness and
joyousness, in some indefinable manner.
I have never heard this species sing in a cage or anywhere near a human
habitation; and it is probably owing to its recluse habits that its
excellent song has not been hitherto noticed. Azara perhaps mistook the
song of this species for that of _Turdus rufiventris_, a very inferior
vocalist.
The nest is made in the centre of a thick bush or tree six or eight
feet above the ground, and is a deep elaborate structure, plastered
inside with mud, and lined with soft dry grass. The eggs are four in
number, oblong; the ground-colour light blue, abundantly marked with
reddish-brown spots.
This Thrush has, I believe, a partial migration in Buenos Ayres. In the
autumn and winter I have frequently observed it in localities where it
is never seen in summer.