(BLACKISH TYRANT.)
+Serpophaga nigricans+, _Burm. La-Plata Reise_, ii. 454 (Paraná);
_Scl. et Salv. Nomencl._ p. 47; _Durnford, Ibis_, 1877, p. 177
(Buenos Ayres); _White, P. Z. S._ 1882, p. 606 (Misiones);
_Barrows, Bull. Nutt. Orn. Cl._ vol. viii. p. 199 (Entrerios).
_Description._--Above dull brownish cinereous; wings and tail
blackish, the coverts and outer secondaries with slight edgings like
the back; crest slight, with a well-marked white basal spot; beneath
paler and rather purer cinereous; under wing-coverts pale cinereous;
bill and feet dark horn-colour: whole length 4·7 inches, wing 2·3,
tail 1·1. _Female_ similar, but vertical spot not so well marked.
_Hab._ S.E. Brazil, Paraguay, La Plata, and N. Patagonia.
This species differs markedly in habits, language, and appearance from
the last. In both sexes the colour is a uniform slaty grey; the tail,
which the bird incessantly opens and flirts like a fan, is black; as
in _S. subcristata_ there is a hidden spot of white under the loose
feathers forming the crest.
It frequents the borders of running streams, seldom being found far from
a water-course; and it alights as often on stones or on the bare ground
as on trees. Male and female are always seen together, for it pairs
for life, and the migration, if it has any, is only partial. It flits
restlessly along the borders of the stream it frequents, making repeated
excursions after small winged insects, taking them in the air, or
snatching them up from the surface of the water, and frequently
returning to the same stand. While thus employed it perpetually utters
a loud, complaining _chuck_, and at intervals the two birds meet, and,
with crests erect and flirting their wings and tails, utter a series of
trills and hurried sharp notes in concert.
The nest is generally placed beneath an overhanging bank, attached
to hanging roots or grass, a few inches above the water; but it is
sometimes placed in a bush growing on the borders of a stream. It is a
neat, cup-shaped, but rather shallow structure, thickly lined inside
with feathers. The eggs are four, pointed, white or pale cream-colour,
with black and grey spots at the large end.