Oilbird
Usually Found: Caves In Northern Territories Of South America
The Oilbird gets its name honestly. It sort of looks like it took a swim in a BP Oil Spill. The species is traditionally found in northern territories of South America, as well as in the Caribbean island, of Trinidad. They can be creepy animals to see because they are not just weird-looking but operate differently compared to most other bird species. First off, most of the nesting colonies are found in caves.
Second, they are nocturnal feeders. They will usually eat fruits only though. Oilbirds are actually the only nocturnal flying fruit-eating bird species on the planet. They have incredible eyesight as most nocturnal birds do, and use echolocation for navigational purposes. To do this, the species creates high-pitched clicking sounds that get up to 2 kHz that we as humans can hear. Although, there are other pitches they produce we cannot hear.