In Chinese we say it's "book from heaven"("天书"), for incomprehensible writings. That's the end of the this English...->Geek->Chinese->heaven sequence
For speakings, yes it's "bird language" ("鸟语"), but the "bird" here is used as a euphemism for male genital.
BTW Chinese is an analytic language, so the grammar is actually very easy.
> In mythology, medieval literature and occultism, the language of the birds is postulated as a mystical, perfect divine language, green language, Adamic language, Enochian, angelic language or a mythical or magical language used by birds to communicate with the initiated.
I read that article a while ago, and until a moment ago assumed this discussion was about it. "Atlas Obscura" and "Strange Maps" are similar enough that I got them mixed up.
EDIT: Looks like Hebrew speakers use Chinese, so we're in a loop.