THE OILBIRD OR GUACHARO 1853 



and has the same stooping motion of the head observable in the owls; it also resem- 

 bles these birds in its erect carriage, the manner in which it sets out the feathers 

 round the ears and neck, and in the power it possesses of turning the head in every 

 direction even over the back, a habit it is constantly practicing." 



THE OILBIRD OR GUACHARO 



Family STEATORNITHID^ 



Forming a family group by itself, the South- American oilbird (Steatomis 

 caripensis] in external appearance is not very unlike a nightjar; to which group 

 it also approximates in habits, only coming out to feed in the dusk of the evening. 

 It is, however, more nearly allied to the frogmouths, having a similar bridged 

 palate, although differing in certain features of the skeleton. The plumage is less 

 soft than in either the goatsuckers or frogmouths; while the beak and the form 

 of the wing are not unlike those of the rollers. The tail .carries ten feathers, and 

 in the wing the third and fourth primary quills are the longest; while the naked 

 metatarsus does not exceed the third toe in length. In the skull the basal rostrum 

 carries articular basipterygoid processes. Measuring from seventeen to twenty 

 inches in total length, the oilbird is chestnut brown in general color. On the 

 upper parts the plumage is marked by numerous dark crossbars; the median wing 

 coverts are ornamented with large white spots, similar spots also occurring on 

 the lateral upper tail coverts; while the under surface is pale chestnut, with a 

 grayish tinge, each feather being marked with three rhomboidal spots of white 

 bordered with black. The beak is chocolate brown; the feet are flesh colored, with, a 

 violet tinge; the claws are gray; and the iris of the eye is black with a narrow dark 

 brown ring. The guacharo is principally known as an inhabitant of the island of 

 Trinidad, where it frequents certain caves, building therein huge nests, having the 

 appearance of large cheeses. The popular name of oilbird is derived on account of 

 the peculiar covering of the nestlings, which are simply masses of yellow fat. Num- 

 bers of the stones of a fruit upon which these birds apparently feed strew the floor 

 of the caves where they dwell. Elsewhere local, the oilbird is found not only in 

 Trinidad, but also from Guiana and Venezuela to Ecuador and Peru, occurring in 

 the latter countries in valleys at an elevation of some seven thousand feet. In the 

 Tatora district of Peru there are several caverns, situated in a very wild country, 

 clad from the base to the summit of the hills with dense virgin forest, frequented by 

 these birds. According to Dr. Stolzmann, if a gun be fired, or any other loud noise 

 made near these caverns, the birds quit their retreats in the nooks and crannies, 

 flying to the roof with piercing cries, and the only way to obtain specimens is to 

 fire at random in the darkness. This, however, is haphazard work, and in the 

 Ninabamba cavern only eleven birds were killed in return for sixty shots. When 

 the birds are tired out, they gradually retire to their hiding places, from which no 

 amount of firing or shouting will induce them to again emerge. When undisturbed, 

 the guacharos quit their retreats as the sun is setting, to fly about the forest; some 



