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."
+Tænioptera dominicana+, _Burm. La-Plata Reise_, ii. p. 460 (Entrerios); _Scl. et Salv. Nomencl._ p. 42; _Durnford, Ibis_, 1877, p. 176 (Buenos Ayres); _White, P. Z. S._ 1883, p. 38 (Buenos Ayres); _Döring, Exp. al Rio Negro, Zool._ p. 42 (Azul, Currumalan); _Barrows, Bull. Nutt. Orn. Cl._ vol. viii. p. 139 (Entrerios, Pigué, Pampas).