How do oilbirds locate and collect fruit from trees?

Oilbirds (Steatornis caripensis) are unique among the order Caprimulgiformes as the only exclusively frugivorous birds. They utilize a combination of sensory adaptations to locate and collect fruit from trees:

• Locating Fruit: Oilbirds possess an efficient olfactory sense, which they use to detect certain aromatic fruit-bearing trees. For non-aromatic fruits, such as those from palm trees, the birds rely on their large, sensitive eyes to locate them visually. While oilbirds use echolocation to navigate in the total darkness of their caves, it is not known to what extent they use this system for foraging outside of the cave environment.12
• Collecting Fruit: Once a tree is located, the actual collection of fruit is dependent on sight. The birds hover while plucking individual fruits with their strong, hook-tipped bills. When feeding on large, compact bunches of fruit, they may briefly cling to the branches with their feet.31

The fruits are swallowed whole, and the large, hard seeds are later regurgitated.1