Guacharo, or OIL-BIRD (Steatornis caripensis), a remarkable South American bird, with characters which seem to unite it to owls and goatsuckers, but differing from the latter in having a strong bill, and being frugivorous. The food of the guacharo consists of hard and dry fruits. It is about the size of a common fowl; the plumage brownish-gray, with small black streaks and dots. The guacharo is a nocturnal bird, a circumstance very singular among frugivorous birds. It spends the day in deep and dark caverns, where great numbers congregate and make their nests. It was first known from Venezuela, but has since been discovered in Peru, Trinidad, and elsewhere in the northern South American region. Humboldt gives a most interesting account, in his Personal Narrative, of a visit to the great Guacharo Cavern in the valley of Caripe, near Cumana. This cavern is visited once a year for the sake of the fat of the young birds, which are slaughtered in great numbers, and their fat melted and stored for use as butter or oil. The clarified fat is half liquid, transparent, inodorous, and will keep for a year without becoming rancid.