Is there anywhere in ME that has a tradition of Whistle speech ? Like what was developed in the Canary Islands centuries after ME.
Whistle speech carrys intelligibly a lot further than shouting. Creating a whistle casting virtue might be an interesting project for a Bonisagus mage.
That exact thing, anachronistic or not, is mentioned in Ancient Magic with the discussion of the Canary Islands though that is not what they call it.
The Dialects section on p94 of Ancient Magic to be more precise.
Once again another reason to require a master index for all the books.
I doubt something like “whistle speech” would have gotten in there.
How about "Canary Islands"
Maybe “Canary Islands, see Purlple Islands.”
Yes. In the village of Aas, in the Pyrenees, in Antia, Greece, and in Kuskoy, Turkey.
(Edit: Added one.)
Centuries after? Sure?
The language spoken... I mean whistled today is the Silbo Gomero, which is indeed centuries older than ME as it is a whistled version of spanish, and we spaniards didn't set foot in the Canary Islands until the XVI century. But it is an adaptation of whistled Guanche, the native language of the islands, probably a Berber language and now a dead language, but not then.
Guanche is supossed to had been simpler than spanish, allowing an easier translation into whistling: whistlers apparently use just about two vowels and four consonants (there seems to be some linguists arguing about that for around 50 years now). Anyway I guess you could adapt hermetic magic to it, as some hermetic magi already use other languages than latin to cast magic. The only issue that I see for an hermetic integration is that it already requires gestures to modify the sounds in the whistle, which probably won't mix well with the already existing spellcasting gestures.
What if it were developed in a lineage of magi with Subtle Magic? (or whatever 5th calls it) No gestures, thus no problem.
Is someone else working on Yondu's Arrow besides our saga's Bonisagus?
Not certain about the others, but by 1220, Turkish kuĹź dili already existed in some form (mostly around the Black Sea rim of Anatolia) - granted it was then a whistled form of Old Anatolian Turkish, not Modern Turkish, but at least it's contemporary in the period.