Enseñando a los murciélagos a decir: Muévete!

Teaching Bats to Say ‘Move Out of My Way’ in Many Dialects

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Egyptian fruit bats at the entrance to their roost in a cave in Israel. A study found that bat pups learn to match their vocalizations to those of the group sounds they are raised in, even if those sounds differ from those of their mothers.CreditEran Amichai

I was raised by grandparents who spoke only Mandarin, so I did not speak English until I went to preschool in Philadelphia. There, guided by English-speaking teachers and surrounded by toddlers babbling in loose English, I adopted the new language quickly.

Young bats may not be so different.

Wild fruit bats, living in crowded roosts, are exposed to calls from hundreds of fellow bats from birth. Most often these calls are made in response to unsolicited physical contact, and essentially amount to a crabby “move out of my way.” In a study published Wednesday in PLOS Biology, a team of Israeli researchers found that bat pups match their vocalizations to the group sounds they are immersed in, even if this “dialect” differs from that of their mothers.

Human babies and toddlers pick up the utterances around them effortlessly. The ability, called vocal learning, is considered critical for our spoken language.

But vocal learning has rarely been proven to exist in animals other than humans or songbirds, said  Yossi Yovel , a neuroecologist at Tel Aviv University who led the study with graduate students 

Yosef Prat and Lindsay Azoulay 

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1:04How Little Bats Say 'Move Over'

How Little Bats Say 'Move Over'

By Lee Harten

The social and vocal interactions of a colony of fruit bats competing for position in a sleeping cluster.Published OnOct. 31, 2017CreditImage by Mickey Samuni-Blank

In nonhuman mammals, much of the evidence for vocal learning “comes from animals that imitate human speech or other artificial sounds,” such as a zoo elephant emulating the Korean spoken by his keepers, Mr. Prat said. What he and his colleagues wanted to know was how an animal learns the sounds of its own species.

To start, the scientists captured 14 wild pregnant Egyptian fruit bats, a highly social and vocal species commonly found in the Middle East. Each mother gave birth in one of three chambers.

In these chambers, the researchers played different soundtracks to the pups continuously, starting from birth. The tracks sampled calls from actual bats, each mimicking a cave or tree roost with 300 bats in it, but featured different ranges of pitch.

For a few months, the bat mothers were also kept in the chambers and would regularly communicate with their offspring. But at 14 weeks, when a pup would normally become independent in the wild, the mothers were set free. At this point, the researchers started recording the pups’ vocalizations every few months until the bats reached adulthood.