People on the mountainous Canary island of La Gomera are embracing a centuries-old language used to communicate across long distances: whistling. Before the internet, phones — even modern roads — Gomerians had no way of getting news quickly to villages on the far sides of enormous ravines and valleys. The piercing sounds of whistling are now a mandatory part of public education on the island. The World’s Gerry Hadden reports from La Gomera.