General Information:
These two bird species are very possibly an example of convergent evolution; the belief that similar environments or selection pressures (in this case, living in caves) can result in two unrelated creatures evolving very similar character traits.
The ability to echolocate in these birds is not close to that of bats but they are proficient at flying in the pitch black of caves, avoiding obstacles, and finding their particular nest.
Both birds use echolocation that can be heard by humans, therefore it is considered elementary. It is assumed that birds use clicking for echolocation because they are short, which allows the bird the detect objects even at short distances, and because click signals do not demand any laryngeal specializations, that bats have.
These two bird species are very possibly an example of convergent evolution; the belief that similar environments or selection pressures (in this case, living in caves) can result in two unrelated creatures evolving very similar character traits.
The ability to echolocate in these birds is not close to that of bats but they are proficient at flying in the pitch black of caves, avoiding obstacles, and finding their particular nest.
Both birds use echolocation that can be heard by humans, therefore it is considered elementary. It is assumed that birds use clicking for echolocation because they are short, which allows the bird the detect objects even at short distances, and because click signals do not demand any laryngeal specializations, that bats have.
This is an example of the anatomy of the bird and where the syrinx is located. The syrinx is where the clicks used for echolocation originate.
Bird ears might not look like human ears but are actually very similar, they just don't have lobes like we do. They are even located around the same spot ours are, below and behind the eyes. The inner ear contains fluid and sensitive hairs that move/vibrate in the presence of sound.
A more specific picture of the parts of the avian ear.