At least 65 million years of evolution separate humans and greater sac-winged bats, but these two mammals share a key feature of learning how to speak: babbling.
Just as human infants babble their way from “da-da-da-da” to “Dad,” wild bat pups (Saccopteryx bilineata) learn the mating and territorial songs of adults by first babbling out the fundamental syllables of the vocalizations, researchers report in the Aug. 20 Science. These bats now join humans as the only clear examples of mammals who learn to make complex vocalizations through babbling.
“This is a hugely important step forward in the study of vocal learning,” says Tecumseh Fitch, an evolutionary biologist at the University of Vienna not involved in the new study. “These findings suggest that there are deep parallels between how humans and young bats learn to control their vocal apparatus,” he says. The work could enable future studies that might allow researchers to peer deeper into the brain activity that underpins vocal learning.
Before complex vocalizations, whether words or mating songs, can be spoken or sung, vocalizers must learn to articulate the syllables that make up a species’s vocabulary, says Ahana Fernandez, an animal behavior biologist at the Museum für Naturkunde in Berlin. “Babbling is a way of practicing,” and honing those vocalizations, she says.