[Added later: the Bora in the Amazon use drums to communicate over long distances - interestingly, using a "compressed" pitch and rhythm system very similar to the whistled system of the Canaries. It's still not its own language, but it's indisputably an outstanding piece of human cultural innovation, and comparison to how Silbo compresses information would be very useful.]
An article in the New Yorker re-romanticizes the idea of "whistled languages", moving from the more famous Silbo of the Canary Islands to a whistled version of Turkish found in northern Turkey. I wrote about Silbo previously, a whistled version of (now) Spanish. (And that's what it should be called - whistled Spanish. In fact Silbo means "whistle.")
As before, I emphasize here that I'm not trying to diminish the significance of these innovations in human culture, just argue against the misconception that these whistled versions of languages are in fact languages in themselves. I'm thrilled that people have caught on to the cultural value and worked to preserve them, and furthermore whistled language provides fertile testing grounds for hypotheses about the comprehension of language, like the lateralization study in Current Biology conducted by Güntürkün, Güntürkün and Hahn cited in the New Yorker. And there are multiple places in the world where a whistled version of a language has developed, for obvious adaptive advantage (hard-to-cross mountains and/or thick forests.) But whistled languages are not distinct languages.
1. Whistled communication is never used as the primary method. People use Silbo to call across canyons to each other (effective and clever) but there was no report of the ear-splitting sound of story-tellers around the campfire (because then they were speaking normally.) I place this claim first because reports of whistled Turkish state that it was used in non-work settings, which on its face would seem to undermine my argument. BUt this loses sight of why it matters whether people use whistled Turkish in more than a few restricted settings - because there is still no such thing as a first-language whistle-language speaker, and certainly there never has been a monolingual. At best, this makes it a pidgin, like Chinook Jargon or Russenorsk.
2. Whistled communication is a whistled version of a primary, "normal" spoken language. If a whistled language is distinct, then when we whisper in English next to each other, that would count as a separate language as well. And of course it doesn't - it's a restricted, rarely-used, context-specific form of communication which makes some phonetic sacrifices due to its usefulness in that setting.
3. Can you learn the Turkish whistled language without learning Turkish? No. Granted, a first-language Turkish speaker might not understand it at first, much like you didn't understand Pig Latinthe first time you heard it. But you can learn Pig Latin - only if you know English first.
No comment on how this bears on my (partly tongue-in-cheek and now mostly abandoned) cultural affinity argument about whistling in other Altaic languages.