Whistling while they work: how shepherds invented a new language in the Canaries

Spanish-speaking shepherds in the Canary Islands have effectively invented a new language in which they communicate through whistling rather than the spoken word, scientists have discovered.

Spanish-speaking shepherds in the Canary Islands have effectively invented a new language in which they communicate through whistling rather than the spoken word, scientists have discovered.

The first scientific study of Silbo - the whistled sounds used by shepherds on the rugged island of La Gomera - has found that it involves the use of the same areas of the brain normally devoted to understanding conventional speech.

La Gomera shepherds are believed to have used Silbo for centuries to communicate simple warnings or instructions over long distances but its simmilarity to everyday language was not fully realised until now.

Scientists from the University of La Laguna on the nearby island of Tenerife used a hospital brain scanner to study five "silbadors", or speakers of Silbo, as they tried to follow pre-recorded messages whistled in Silbo.

The researchers compared the way the men used their brains to carry out this task with the way they followed similar messages spoken to them in Spanish. The results were then compared with the brain scans of Spanish speakers who could not understand Silbo yet listened to the same whistled messages. The scientists found that the brains of non-Silbo "speakers" treated the sounds in a very different way to the shepherds.

The researchers also found that the brains of the silbadors processed the whistling sounds of Silbo in a similar manner to the way the rest of us process the sounds of a spoken language.

David Corina of the University of Washington in Seattle, a co-author of the study published in the journal Nature, said that the findings show how areas of the brain dedicated to language can also be used for other forms of non-verbal communication.

"Our results provide more evidence about the flexibility of human capacity for language in a variety of forms," Dr Corina said.

The brain scans showed that when the shepherds were trying to understand whistled sounds, areas of the brain's left hemisphere that are normally dedicated to language were activated - just as they are when deaf people communicate in sign language.

"These data suggest that left hemisphere language regions are uniquely adapated for communicative purposes, independent of the modality of the signal," Dr Corina said.

"The non-Silbo speakers were not recognising Silbo as a language. They had nothing to grab onto so multiple areas of their brains were activated," he said. "But the silbadores were analysing differently, as a language, and engaging those areas associated with language."

The whistled language of Silbo is thought to have been introduced to the Canaries by Berbers from North Africa. Modern Silbo effectively condenses Spanish into just two vowels and four consonants.

"You wouldn't call Silbo a fully-fledged language. Children are not born whistling it. In general, anything in Spanish can be translated into Silbo, but context is very important," Dr Corina said.

Silbo is used by shepherds to communicate simple messages such as "open the gate" or "there is a stray sheep" and is essentially an occupation-based language rather than one used for general conversations.