The world's most unique bird mimics bats, flying at night and feeding on fruit (video).

The Earth is home to an astonishing number of species, and some continue to amaze scientists for years. For instance, the remarkable oilbirds (Steatornis caripensis), or guácharos, are the only flying birds that are nocturnal and feed on fruits. Moreover, they share some similarities with bats, as reported by IFLScience.

These fascinating birds can be found in neotropical habitats in their native South America: as far south as Bolivia and north in countries such as Colombia and Venezuela. It is noteworthy that in these regions, oilbirds are often referred to as "guácharo." Despite their bat-like behavior, guácharos are considered relatives of nightjars and potoos, and they have a quirky appearance—such as small whiskers surrounding their beaks.

Previously, the German naturalist Alexander von Humboldt noted that oilbird chicks are incredibly well-fed, making them a valuable resource for the indigenous peoples of Venezuela. Researchers found that indigenous communities used young birds to harvest their abundant fat, which was then used in cooking. It is also known that local residents collected chicks from caves. Interestingly, it was once believed that this species nests exclusively in caves, with colonies sometimes reaching up to a thousand individuals.

However, in a 2009 study, scientists discovered that the birds actually spend time in caves only every third day—the rest of the time, they quietly perch on trees in the tropical forest, where they regurgitate seeds.

Members of this species also lead a nocturnal lifestyle, which is not particularly unusual for birds, but what is more intriguing is that they feed exclusively on fruits and navigate using echolocation. In fact, oilbirds are considered the only nocturnal, flying, fruit-eating birds in the world.

Researchers found that oilbirds use echolocation to help them navigate in the dark caves, but unlike most bat species, we humans can hear it. They also emit a series of short, sharp cries and whines, which may well be the reason for their name guácharo, as it means "crier" in Spanish.

However, the comparison with bats ends at navigation. While bats also use echolocation to find food, there is no substantial evidence that oilbirds do the same. But don’t worry, oilbirds, we still love you.