IUCN Red List of threatened species & classification (Extinct, Vulnerable, Endangered etc.) 

IUCN Red Data List categories and Classification Criteria. Concept of Threatened Species.
The IUCN Red List of Threatened Species™ is the world's most comprehensive inventory of the global conservation status of plant and animal species. It uses a set of quantitative criteria to evaluate the extinction risk of thousands of species. These criteria are relevant to most species and all regions of the world. With its strong scientific base, the IUCN Red List is recognised as the most authoritative guide to the status of biological diversity.
#iucnredlist #iucnconservationclassification