Gawain rode on without a rest, his heart rejoicing at the glorious weather and at the sound of the birds, so clear and high: it was as if they were talking, telling each other of their love, as they warbled away in their high tongue.
Wauchier of Denain, Second Continuation of Perceval
The concept of a language of the birds is used both literally and metaphorically to refer to some combination of:
- A language with which you could understand what birds seem to be saying in all their songs.
- The Adamic language - that is, the original language all people spoke, before the Tower of Babel1.
- A divine, or at least angelic, language - more true, precise or perfect than other tongues.
Again, references can differ in which of these points they mean literally and which they hold more loosely.
Two constructed (or reconstructed) languages that sought - by secret transmission, divine inspiration, or whatever - to be some sort of language of the birds are Edenic and the Lingua-Ignota.