Sumatra

Distributed in the Sundaland region (Thai-Malay Peninsula, Sumatra, Borneo, Java and adjacent smaller islands), langurs of the genus Presbytis are one of the most threatened groups of Asian primates. According to the IUCN Red List of Threatened Species, 24 of the 28 taxa (>85%) are threatened with extinction (listed as Critically Endangered, Endangered or Vulnerable). One taxon is classified as Near Threatened and one as Data Deficient. Only two Presbytis taxa are considered as Least Concern.

Les pages qui suivent ont pour origine l'esquisse d'un ouvrage que l'auteur comptait présenter au concours institué, en 1913, par l'Institut Royal Colonial d'Amsterdam, dont le programme stipulait une "Description succincte des Terres et Peuples de Sumatra".