Dolphins give each other names and use them for life
Bottlenose dolphins develop unique signature whistles within the first few months of life — personal acoustic identities equivalent to names. Other dolphins learn and use these whistles to address specific individuals, and a dolphin will respond to its name even when called by a dolphin it has never met. Researchers found that dolphins retain these name whistles for at least 20 years. This is the clearest evidence of non-human animals using arbitrary sound labels to refer to individuals.
Naming is considered a uniquely human social technology, tied to language and identity. Discovering dolphins do it independently rewrites our understanding of what names actually are.
“Dolphins have names. Each one develops a unique signature whistle as a baby, and other dolphins use it to address them. They remember each other's names for 20+ years. 🐬 #OddlyHuman”