Oilbird
The Oilbird (Steatornis caripensis) also known as the Guácharo, is a species of bird related to nightjars. It is found in the northern areas of South America from Guyana and the island of Trinidad to Venezuela, Colombia, Ecuador, Peru and Bolivia. It is a rare vagrant to Costa Rica, Panama and Aruba. Its natural habitat is forests and woodland with caves. It is a seasonal migrant and moves from its breeding caves in search of fruit trees.
The adult oilbird is 16 to 19 inches long, with a wingspan of 36 inches. It has a flattened, powerfully hooked bill surrounded by deep chestnut rectal (the opening of the mouth) bristles that are up to 2 inches long. It is mainly reddish-brown with white spots on the nape and wings. Lower parts are cinnamon-buff spotted with white. The stiff tail feathers are a rich brown spotted with white on either side. The feet of this bird are small and nearly useless, other than for clinging to vertical surfaces. It is capable of hovering and twisting flight, which allows it to navigate the tight spots in its cave habitat.
This nocturnal species is a specialist feeder on the fruit of the Oil Palm and tropical laurels. All other Nightjar species and their relatives are insectivores. During the day these gregarious birds rest on cave ledges. The nest is a heap of droppings, usually above water, on which 2 to 4 white, glossy eggs are laid which soon become stained brown. The young become very fat before fledging the nest, weighing up to half as much as adults do.
Although the Oilbird forages by sight, it is one of only a few birds, and the only nocturnal one, known to navigate by
echolocation in sufficiently poor light conditions, using a series of sharp audible clicks for this purpose. It also produces a variety of harsh screams while in its caves. Entering a cave with a light provokes these raucous calls.