OIL-BIRD. 
89 
loud hissing noise, and has the same stooping motion of the head observable in the 
owls; it also resembles 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 
practising.” 
The Oil-Bird or Guacharo. 
Family S TEA TORRITHIDjE. 
Forming a family group by itself, the South American oil-bird (Steatornis 
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 frog-mouths, having a similar bridged 
palate, although differing in certain features of the skeleton. The plumage is less 
soft than in either the goatsuckers or frog-mouths; 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 17 to 20 inches in total 
length, the oil-bird is chestnut-brown in general colour. On the upper-parts the 
plumage is marked by numerous dark cross-bars; 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 greyish tinge, 
each feather being marked with three rhomboidal spots of white bordered with black. 
The beak is chocolate - brown; the feet are flesh-coloured, with a violet tinge; 
the claws are grey; and the iris of the eye is black with a narrow dark brown 
ring. The gaucharo 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 oil-bird is derived on account of the peculiar 
covering of the nestlings, which are simply masses of yellow fat. Numbers of the 
stones of a fruit upon which these birds apparently feed strew the floor of the 
caves where they dwell. Elsewhere local, the oil-bird 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 
of them rising to a considerable elevation, apparently in pursuit of moths. Their 
