Vocal Mimicry Signals Mammal Friendships

Longitudinal recordings of female vampire bats show individuals shift their ultrasonic contact calls to match those of new partners as they form grooming and food‑sharing bonds. The acoustic convergence tracks social interactions over years, suggesting vocal learning is used beyond kin recognition to actively forge affiliative ties. — If vocal convergence is a general social tool across mammals, it reframes questions about the evolution of language, social cognition, and how conservation or captive management might disrupt or harness communication to support group stability.