1854 THE PICARIAN BIRDS 



of them rising to a considerable elevation, apparently in pursuit of moths. Their 

 noiseless flight much resembles that of goatsuckers, but in descending rapidly the 

 wings are frequently raised and held together in a point. Their principal food con- 

 sists of the fruit of the nectandra trees; these fruits being seized by the birds while 

 in full flight from the tips of the slender boughs which would be too frail to 

 bear the weight of the robbers. For seizing such fruits the hooked and powerful 

 bill of the oilbird is most admirably adapted. The rapidity with which the 

 guacharos feed is remarkable; two specimens killed by Stolzmann early one 

 evening having their crops empty, whereas one shot a quarter of an hour later had 

 swallowed seven fruits, and a second bagged after another quarter of an hour no 

 less than eleven. The same observer remarks that it would be curious to know 

 what the birds did for the remainder of the night, after having satisfied their 

 appetite, for he has seen them on moonlight evenings on the wing as late as eleven. 

 The note of the guacharo is harsh and disagreeable, and has been compared to the 

 syllables cri-cri-cirri; although there is another cry which cannot be rendered in 

 words. From observations on a young bird, in the gray nestling plumage, Stolz- 

 mann found that the large nectandra stones are regurgitated after the fleshy cover- 

 ing has been digested. This rejecting process is accomplished without any apparent 

 effort on the part of the bird; a slight movement of the feathers of the throat takes 

 place, the beak opens gently, and the stone appears; while, if any of the fleshy 

 covering still adheres to it, the bird picks it off. The old birds apparently cast up 

 the stones during flight, and although no insects were found in the stomachs of the 

 specimens shot, Stolzmann is of opinion that guacharos are partly insectivorous. 

 Humboldt and Bonpland visited the celebrated cavern of Caripe, from whence these 

 birds take their specific name, and the following account of the visit is taken from 

 a biographical work. "The Indians," it is written, "showed the travelers the 

 nests of the guacharos by fixing a torch to a long pole. These nests were fifty or 

 sixty feet high above their heads, in holes in the shape of funnels, with which the 

 roof of the grotto was pierced like a sieve. The noise increased as the travelers 

 advanced, and the birds were scared by the light of the torches. When this noise 

 ceased for a few minutes, around them they heard at a distance the plaintive cry of 

 the birds roosting in other ramifications of the cavern, and it seemed as if different 

 groups answered each other alternately. The Indians were in the habit of entering 

 this cavern once a year, near midsummer; when they went armed with poles, with 

 which they destroyed the greater part of the nests. At that season several thousand 

 birds were killed, and the old ones, as if to defend their brood, hovered over 

 the heads of the Indians, uttering terrible cries. The young, which fell to the 

 ground, were opened on the spot for their fat. At the period commonly called at 

 Caripe the oil harvest, the Indians built huts with palm leaves near the entrance, 

 and even in the porch of the cavern. There, with a fire of brushwood, they melted 

 in pots of clay the fat of the young birds just killed; this fat being known by the 

 name of guacharo butter." The nest is formed of clay; and the eggs, varying from 

 two to four in number, have a thick shell, which is at first chalky white, but 

 by contact with the nest becomes yellowish green. 



