The Emberá people of the Baudó river, whose language (Emberá-Baudó) is classified as threatened. Credit: Rodrigo Camara Leret, Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University

Languages are dying out faster than the rate of biodiversity loss, and the leading reason for the loss of many native tongues is economic growth, says a new study led by the University of Cambridge.

Two language loss hotspots were identified by the study, published online in the Proceedings of the Royal Society B.

One was in economically well developed regions such as north-western North America and northern Australia; another was in economically developing regions of the tropics and the Himalayas. The latter was identified as future hotspots while the former was where conservation efforts are needed today.

Applying criteria to huge language datasets as defined by the International Union for Conservation of Nature to identify endangered species, like small population size, small geographical habitat range and population change, they found that levels of GDP (Gross Domestic Product) per capita correlated most with the loss of language diversity.

The more successful economically, the more rapidly language diversity was disappearing.

"As economies develop, one language often comes to dominate a nation's political and educational spheres. People are forced to adopt the dominant language or risk being left out in the cold – economically and politically," said Dr Tatsuya Amato, from the University of Cambridge's Department of Zoology.

In Australia, aboriginal languages like the extinct Margu and Rembarunga are increasingly disappearing from the northern territories. So also, in the northwest corner of North America, Upper Tanana, for example, a language spoken by indigenous Athabaskan people in eastern Alaska, had only 24 active speakers in 2009, and was no longer being acquired by children. The Wichita language of the Plains Indians, now based in Oklahoma, is also dying.

However, the study could only glean details about the rate of decline or growth for 9%, or 649, of the 6909 languages surveyed.

Without denying the aspirations of growing populations that gravitate towards the language that spurs growth, the authors pointed to the need for conserving human cultural diversity. Language is one aspect of this diversity.

Some experts think that there are more factors than economic growth to be blamed for language loss. Current attitudes toward endangered tongues stem in large part from historical policies that forced young American Indians to eschew their native tongues in order to learn English, a linguistic expert told Science. Generations of disease, murder, and genocide have also played an important role.