Central Okinawan is endangered with 1 million speakers

^ Japan Focus: Language Loss and Revitalization in the Ryukyu Islands, Patrick Heinrich, posted November 10, 2005. Also | What leaves a mark should no longer stain: Progressive erasure and reversing language shift activities in the Ryukyu Islands, 2005, citing Hattori, Shirō (1954) 'Gengo nendaigaku sunawachi goi tokeigaku no hōhō ni tsuite' [‘Concerning the Method of Glottochronology and Lexicostatistics’], Gengo kenkyū [Journal of the Linguistic Society of Japan] v26/27

from http://en.wikipedia.org/wiki/Ryukyuan_language#Political_language_status