Two whistlers might struggle to understand each other, particularly during their first encounters — and need to ask each other to repeat sentences — like strangers who speak the same language with different accents. But “after whistling together for a while, their communication becomes as easy as if speaking Spanish,” Mr. Correa said.
As is the case in many languages, whether whistled or not, there is a generation gap on La Gomera.
Ciro Mesa Niebla, a 46-year-old farmer, said he struggled to whistle with a younger generation trained at school because, he said, “I’m a mountain guy who learned at home to whistle the words our family used to farm, but I don’t have the vocabulary of these kids who learn salon whistling, which is a bit too fancy for me.”
Some older residents have also stopped whistling because of tooth problems. Mr. Márquez continues to whistle with his dentures, “but it’s not as easy and as loud as when I could press my finger onto my real teeth,” he said.
With its distinct geography, it’s easy to see why whistling came into use on the Canaries; on most of the islands, deep ravines run from high peaks and plateaus down to the ocean, and plenty of time and effort are required to travel even a short distance overland. Whistling developed as a good alternative way to deliver a message, with its sound carrying farther than shouting — as much as two miles across some canyons and with favorable wind conditions.
Older residents on La Gomera recall how Silbo was used as a warning language, particularly when a police patrol was spotted searching for contraband. In a recent fictional movie, “The Whistlers,” Silbo is used by gangsters as their secret code language.
Some other islands in the archipelago have their own whistling languages, but their use has faded, though another island, El Hierro, recently began teaching its version. “Silbo was not invented on La Gomera, but it is the island where it was best preserved,” said David Díaz Reyes, an ethnomusicologist.