(BLACK-CROWNED TYRANT.)
+Tænioptera coronata+, _Burm. La-Plata Reise_, ii. p. 459; _Scl. et
Salv. Nomencl._ p. 42; _Durnford, Ibis_, 1877, p. 176 (Buenos
Ayres); _White, P. Z. S._ 1882, p. 603 (Buenos Ayres); _Döring,
Exp. al Rio Negro, Zool._ p. 42 (R. Colorado); _Barrows,
Bull. Nutt. Orn. Cl._ vol. viii. p. 138 (Entrerios). +Xolmis
variegata+, _Darw. Zool. Voy. Beagle_, iii. p. 54 (Santa Fé).
_Description._--Above cinereous; rounded summit of head black,
broad front and band encircling the black of the head white; wings
blackish, upper coverts cinereous, edgings of middle and greater
coverts and of outer secondaries whitish; tail blackish, margins of
outer webs of external tail-feathers white; beneath white; under
wing-coverts and a large portion of the inner webs of the remiges,
except of the two outer primaries, white; bill and feet black; whole
length 7·8 inches, wing 4·6, tail 3·1. _Female_ similar.
_Hab._ Argentine Republic, Uruguay, and Paraguay.
In this species the sexes are alike. The crown is black and composed
of loose feathers; the forehead, and a broad line over the eye which
extends nearly round the head, also all the under plumage, pure white;
neck and back clear grey; quills black.
This Tyrant is a solitary bird, though often many individuals are found
within call of each other, and they sometimes even unite in a loose
flock. It is found throughout the Argentine country, ranging south to
the Rio Negro, in Patagonia, but abounds most on the Buenos-Ayrean
pampas, where it performs a partial migration. Most of the _Tæniopteræ_
seek their food by preference on the bare level ground, or where the
vegetation is most scanty. This species varies somewhat in habits, and
seldom runs on the ground, and chiefly inhabits the desert plains,
where the large grasses flourish. On one occasion when I was with an
expedition on the pampas for several weeks, every day a number of these
birds would gather and follow us; perched here and there on the tall
grasses with their bosoms toward us, they often looked at a distance
like large white flowers. Old gauchos have told me that fifty years ago
they were abundant all over the pampas, but have disappeared wherever
the giant grasses have been eaten down, and have given place to a
different vegetation.
Their note is a long, low whistle, the usual language of the
_Tæniopteræ_; but in this species it is very like a human whistle, on
account of which the bird is named _Boyero_ (ox-driver) on the pampas.
One severe winter great numbers of them appeared in the neighbourhood
of Buenos Ayres, and it was amusing to see the dogs thrown into a great
state of excitement by the low whistling notes heard perpetually from
all sides. Every few moments they would start up and stare about them
to ascertain where the deceptive call came from, and in spite of many
disappointments they would occasionally all rush away, loudly barking,
into the plantation, convinced that some person there was whistling to
call them.
The Black-Crown makes a somewhat shallow nest in a bush or large clump
of grass, and lays four white eggs, with large dark red spots, chiefly
at the big end.
I cannot refrain from quoting a passage from Mr. Barrows's paper,
descriptive of the lively temper and habits of this bird:--
"This species frequently persecutes smaller birds in a way which seems
to imply pure love of mischief. One afternoon in July, when the river
had fallen some feet after an unusual rise, I was walking along the
lines of drift left by the falling water, and watching the different
birds which were picking up insects or other food from the wind-rows.
A score or two of the little chestnut-backed _Centrites_ were running
about, and here and there a _Tænioptera_ was looking quietly on.
Suddenly I heard a chirp of distress, and looking up saw one of
these small birds apparently making every effort to escape from a
_Tænioptera_, which was following in full chase. The two birds were
hardly a length apart and both going at full speed, doubling and dodging
in a way that would have done credit to a bat. The chase lasted perhaps
for half a minute, when the smaller bird alighted, and at once the other
also alighted and began running about unconcernedly and picking up food.
But the instant the smaller one made a start his enemy was at his heels
(or more properly his tail) again, and he was forced to alight. This was
repeated so often that I was on the point of shooting the pursuer,
when, without any notice, he flew quietly off, and resumed his usual
demeanour. It looked like a case of simple spite, for even if there were
twenty other birds about, one seemed to be followed without regard to
the rest."
I have often watched _Tæniopteræ_ of different species, also
_Myiotheretes rufiventris_ behaving in a similar way, and agree with Mr.
Barrows that it is "an _amusement_ in which the larger bird indulges
simply for the pleasure derived from the exercise of his power."