"This Ancient Whistling Language is in grave danger of dying out" PBS NewsHour 9/5/2017

Excerpt

SUMMARY:  In the Greek island village of Antio, home to the world's most endangered language, aging residents communicate across hillsides through whistles [language], a specific system of communication believed to date back to Ancient Greece.  Special correspondent Malcolm Brabant reports on how they hope to save their language from extinction and what it has in common with Twitter.