GUACHARO (said to be an obsolete Spanish word signifying one that cries, moans or laments loudly), the Spanish-American name of what English writers call the oil-bird, the _Steatornis caripensis_ of ornithologists, a very remarkable bird, first described by Alexander von Humboldt (_Voy. aux reg. equinoxiales_ i. 413, Eng. trans. iii. 119; _Obs. Zoologie_ ii. 141, pl. xliv.) from his own observation and from examples obtained by Aime J. A. Bonpland, on the visit of those two travellers, in September 1799, to a cave near Caripe (at that time a monastery of Aragonese Capuchins) some forty miles S.E. of Cumana on the northern coast of South America. A few years later it was discovered, says Latham (_Gen. Hist. Birds_, 1823, vii. 365), to inhabit Trinidad, where it appears to bear the name of _Diablotin_;[1] but by the receipt of specimens procured at Sarayacu in Peru, Cajamarca in the Peruvian Andes, and Antioquia in Colombia (_Proc. Zool. Society_, 1878, pp. 139, 140; 1879, p. 532), its range has been shown to be much greater than had been supposed. The singularity of its structure, its curious habits, and its peculiar economical value have naturally attracted no little attention from zoologists. First referring it to the genus _Caprimulgus_, its original describer soon saw that it was no true goatsucker. It was subsequently separated as forming a subfamily, and has at last been regarded as the type of a distinct family, _Steatornithidae_--a view which, though not put forth till 1870 (_Zool. Record_, vi. 67), seems now to be generally deemed correct. Its systematic position, however, can scarcely be considered settled, for though on the whole its predominating alliance may be with the _Caprimulgidae_, nearly as much affinity may be traced to the _Strigidae_, while it possesses some characters in which it differs from both (_Proc. Zool. Society_, 1873, pp. 526-535). About as big as a crow, its plumage exhibits the blended tints of chocolate-colour and grey, barred and pencilled with dark-brown or black, and spotted in places with white, that prevail in the two families just named. The beak is hard, strong and deeply notched, the nostrils are prominent, and the gape is furnished with twelve long hairs on each side. The legs and toes are comparatively feeble, but the wings are large. In habits the guacharo is wholly nocturnal, slumbering by day in deep and dark caverns which it frequents in vast numbers. Towards evening it arouses itself, and, with croaking and clattering which has been likened to that of castanets, it approaches the exit of its retreat, whence at nightfall it issues in search of its food, which, so far as is known, consists entirely of oily nuts or fruits, belonging especially to the genera _Achras_, _Aiphanas_, _Laurus_ and _Psichotria_, some of them sought, it would seem, at a very great distance, for Funck (_Bull. Acad. Sc. Bruxelles_ xi. pt. 2, pp. 371-377) states that in the stomach of one he