Things can get pretty loud in Egyptian fruit bat colonies. These highly social critters live in groups of up to 50,000 individuals—all clicking and chirping and squeaking. But as Jason Bittel reports for National Geographic, a new study suggests that all this noise plays a fundamental role in teaching baby bats to communicate.
Researchers at Tel Aviv University were curious if bat pups take language-learning cues from their mothers or from the general din that surrounds them. So they collected 14 pregnant Egyptian fruit bats and separated them into three colonies, where the mothers raised their babies after they gave birth. Each group was played recordings of different “dialects,” or vocalizations: one was unadulterated audio from a bat colony, another had been manipulated to include more high-pitched calls than would be typical in an Egyptian bat colony, and another was manipulated to include more low-pitched calls.
After around three months, a time when the pups would normally wean, the mothers were released back into the wild. By the age of 17 weeks, pups from all three groups were communicating in dialects that matched the recordings that had been played to them—and not the vocalizations of their mothers.
“The difference between the vocalizations of the mother bat and those of the colony are akin to a London accent and, say, a Scottish accent,” lead researcher Yossi Yovel tells Agence France Presse. “The pups eventually adopted a dialect that was more similar to the local ‘Scottish’ dialect than to the ‘London’ accent of their mothers.”
The team recently published its findings in the journal PLOS Biology. The results of the study were not necessarily surprising, Yovel tells Rachael Lallensack of Nature; it makes sense that bat pups, which live in dark and crowded quarters, would pick up sounds from the thousands of critters that surround them. But “it was never demonstrated before now,” Yovel says.
Only a few other mammals— among them whales, dolphins and humans—learn to communicate by mimicking the noises around them. It is possible, then, that further studies into the processes of bat communication can help us better understand the ways that humans learn language.