THE FERN-OWL. 281 



are many. In South America, particularly, they abound t 

 the curious retreats of one species of these birds are thus- 

 described by the celebrated traveller, M. De Humboldty 

 who visited a dark chasm in the rocks called the Cavern 

 of Guacharo, frequented by a species (Caprimulgus 

 steatornis) whose young were caught to furnish oil : 



" A frightful noise, made by these birds, issued from 

 the dark recesses of the cavern ; their shrill and piercing 

 tones reverberated from the arched roofs, and were re- 

 echoed from the depths of the cave. The Indians, by 

 fixing torches to the end of a long pole, pointed out their 

 nests, arranged in funnel-shaped holes, with which the 

 whole roof of the grotto was riddled. As the travellers 

 advanced, the noise increased, the flare of the torches 

 alarming the birds still more. When it ceased for a few 

 minutes, distinct moans were heard from other remote- 

 branches of the cavern, the alternate responses of other 

 flocks of these birds. The Indians, every year about 

 Midsummer, descend into the cave furnished with poles 

 for the purpose of destroying the nests. At this time 

 many thousands of birds are killed, and the old ones, as 

 if to protect their broods, hover over the heads of the 

 Indians, uttering the most dreadful shrieks. The young 

 that fall to the ground are immediately ripped open, to- 

 procure a sort of unctuous or fatty substance with which 

 they are then loaded. At this period, which is com- 

 monly termed the oil-harvest, the Indians construct little 

 habitations of palm-leaves, close to the opening, and even 

 in the mouth of the cavern. Here the grease of the 

 young birds just killed is melted over a fire of dry sticks, 

 and run into pots of white clay. This grease, known 

 by the name of Guacharo butter or oil, is semi-liquid,, 

 transparent, and without smell, and so pure that it may 

 be kept a twelvemonth without becoming rancid. At a, 

 neighbouring convent, visited by these travellers, no oil 

 but that of the cavern was used in the monks' kitchen,, 

 and it was never found to give to any dish a disagreeable 

 taste or smell." 



