A study of fruit bat pups shows how bats use vocal learning, commonly thought of as uniquely human, to pick up new accents.
Image: Jens Rydell
The way human children speak is highly influenced by their surroundings—plop a toddler down in Brooklyn for long enough, and she'll learn to talk like a Brooklynite. Send a kid to London, and she'll grow up to speak with that dialect.
Scientists have discovered that humans might not be alone in this: Fruit bats aren't so different from us, at least when it comes to vocal learning, according to a new study. In the darkened cacophony of a bat colony, where up to thousands of bats are chirping and squeaking, bat pups are influenced by the crowd, not by their own mothers.
As part of their study, Dr. Yossi Yovel of Tel Aviv University and his students Yosef Prat and Lindsay Azoulay examined bat vocalizations by playing a recording of a certain "dialect" to pups for a year. They caught pregnant bats from wild roosts in central Israel and brought them back to artificial caves to give birth, recorded the mother's' vocalizations, then released the mothers back into the wild. The pups were kept in an artificial "roost" that resembled how they'd be raised in the wild.
After the baby bats were exposed to a sound mix that included their mom's voice, intermingled with hundreds of other like-sounding bat dialects, the scientists found that they grew up to mimic the crowd.
Bats sound a lot like mice: They each chirp and chitter in ways that sounds indistinguishable from one another to us, but to each other, are as varied between individuals as our own voices.
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