Steatornithidae – Oilbird
The Steatornithidae family has but one member, the oilbird, locally known as the guácharo; it is a bird species found in the northern areas of South America (including the island of Trinidad. Nesting in colonies in caves, oilbirds are nocturnal feeders on the fruits of the oil palm and tropical laurels. They are the only nocturnal flying fruit-eating birds in the world (the kakapo is flightless). They forage at night, with specially adapted eyesight. However they navigate by echolocation in the same way as bats, and are one of the few kinds of birds known to do so. They produce a high-pitched clicking sound of around 2 kHz that is audible to humans.
It is a large, slim bird at 40cm to 49cm with a wing span of 95 centimetres. It has a flattened, powerfully hooked, bill surrounded by deep chestnut rictal bristles up to 5 centimetres long. The adult weighs 350g to 475g, but the chicks can weigh considerably more, at up to 600 grams when their parents feed them a good deal of fruit before they fly. 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 are small and almost useless, other than for clinging to vertical surfaces. The long wings make it capable of hovering and twisting flight, which enables it to navigate through restricted areas of its caves.
The oilbird ranges from Guyana and the island of Trinidad to Venezuela, Colombia, Ecuador, Peru, Bolivia and Brazil in forests and woodlands with caves. It is a seasonal migrant, moving from its breeding caves in search of fruit trees. It has occurred as a rare vagrant to Costa Rica, Panama and Aruba. The Guácharo Cave (Oilbird Cave), in the mountainous Caripe district of northern Monagas, Venezuela, is where Alexander von Humboldt first studied the species.
The one species in the family is:
Oilbird Steatornis caripensis