Cowbirds have a specific language when teaching their young
As you probably know, like the cuckoo, cowbirds lay their eggs in other bird species’ nests and their young have to reconnect with them when they grow up, but they have to use a specific password to find their relatives. “Juvenile cowbirds readily recognize and affiliate with other cowbirds.
That’s because they have a secret handshake or password,” according to Science Daily. In other words, they use “a specific chatter call” to reconnect with their own species.