Oilbirds

The oilbird, locally known as the "guácharo", is a bird species found in the northern areas of South America including the island of Trinidad. They are the only nocturnal flying fruit-eating birds in the world. They forage at night, with specially adapted eyesight. However they navigate by echolocation in the same way as bats, one of the few birds to do so. They produce a high-pitched clicking sound of around 2 kHz that is audible to humans.