title: Global distribution and drivers of language extinction risk.
abstract: Many of the world's languages face serious risk of extinction. Efforts to prevent this cultural loss are severely constrained by a poor understanding of the geographical patterns and drivers of extinction risk. We quantify the global distribution of language extinction risk-represented by small range and speaker population sizes and rapid declines in the number of speakers-and identify the underlying environmental and socioeconomic drivers. We show that both small range and speaker population sizes are associated with rapid declines in speaker numbers, causing 25% of existing languages to be threatened based on criteria used for species. Language range and population sizes are small in tropical and arctic regions, particularly in areas with high rainfall, high topographic heterogeneity and/or rapidly growing human populations. By contrast, recent speaker declines have mainly occurred at high latitudes and are strongly linked to high economic growth. Threatened languages are numerous in the tropics, the Himalayas and northwestern North America. These results indicate that small-population languages remaining in economically developed regions are seriously threatened by continued speaker declines. However, risks of future language losses are especially high in the tropics and in the Himalayas, as these regions harbour many small-population languages and are undergoing rapid economic growth.
authors.affiliation: Conservation Science Group, Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK amatatsu830@gmail.com.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Amano
authors.affiliation: Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: Brody
authors.initials: B
authors.lastname: Sandel
authors.affiliation: Research Laboratory for Archaeology and the History of Art, School of Archaeology, University of Oxford, Oxford OX1 2HU, UK Department of Ecology and Evolutionary Biology, Cornell University, Corson Hall, Ithaca, NY 14853-2701, USA.
authors.forename: Heidi
authors.initials: H
authors.lastname: Eager
authors.affiliation: Ecole Polytechnique, Route de Saclay, 91120 Palaiseau, France.
authors.forename: Edouard
authors.initials: E
authors.lastname: Bulteau
authors.affiliation: Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Aarhus 8000 C, Denmark.
authors.forename: Jens-Christian
authors.initials: JC
authors.lastname: Svenning
authors.affiliation: Center for Macroecology, Evolution, and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
authors.forename: Bo
authors.initials: B
authors.lastname: Dalsgaard
authors.affiliation: Center for Macroecology, Evolution, and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
authors.forename: Carsten
authors.initials: C
authors.lastname: Rahbek
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Davies
authors.affiliation: Conservation Science Group, Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
authors.forename: William J
authors.initials: WJ
authors.lastname: Sutherland
mesh_terms: D003247:Conservation of Natural Resources; D053476:Extinction, Biological; D006801:Humans; D007802:Language; D011156:Population Density; D012306:Risk
keywords: cultural conservation; cultural diversity; endangered languages; human ecology; language conservation; macroecology