Bat besties match voices: Study shows vampires copy close companions

A curious idea often circles human speech patterns. People subtly mirror sounds heard from friends. Similar behaviour appears in wild animals too. New research now reveals that vampire bats do likewise. The finding adds insight into their quiet social world.

How do vampire bats match each other's calls?
A study in Proceedings of the Royal Society B reports strong evidence. Female vampire bats adjust calls to match companions. Scientists brought together familiar bats and strangers. They placed them carefully inside controlled lab cages. Researchers then watched friendships develop over time. Vampire bats live in highly social matrilineal groups. Females maintain relationships with unrelated partners. They share blood meals with trusted friends only. They groom allies and trade vital food support. The team tracked these behaviours inside the experiment. Grooming and feeding helped reveal bonded pairs. Matched calls were then compared across groups.

How were the bats' sounds recorded and analysed?
Bats communicate in high ultrasonic frequencies. Humans cannot hear these contact calls naturally. Special audio equipment captured each call clearly. Spectrograms visualised frequency patterns for later study. Nearly 700,000 calls were analysed over years. Ninety-five bats took part in recordings. Each bat entered its own recording booth. Researchers compared calls across social interactions.

What did scientists learn about matched calls?
Lead author Julia Vrtilek explained the findings. Bats changed calls when living with new companions. They matched familiar partners instead of louder neighbours. Food-sharing pairs grew more similar in sound. Less friendly pairs showed weaker vocal alignment. Co-author Grace Smith Vidaurre highlighted vocal learning. Bats learn calls through repeated daily contact. They do not rely solely on inherited patterns. Senior author Gerald Carter noted similarities to accents. Matching calls may help identify familiar partners. Shared sounds could strengthen developing relationships. They might also aid reunions in noisy colonies. Similar vocal behaviour appears in dolphins and elephants. Parakeets and monkeys show comparable traits too.