The International Union for the Conservation of Nature (IUCN) defines a species as “critically endangered” if it is facing an extremely high risk of becoming extinct in the wild. The full criteria can be found here.
The species listed here are the most threatened non-marine vertebrates of Southeast Asia and require urgent conservation action. While there is substantial data on some of these species, we face a dearth of information for many more. Organizations within the international conservation community are joining forces to minimise impending extinctions in this part of the world, exacerbated by habitat loss, trade and hunting.
Reference: IUCN. (2012). IUCN Red List Categories and Criteria: Version 3.1. Second edition. Gland, Switzerland and Cambridge, UK: IUCN. iv + 32pp.