The report ‘Living Planet’ is released every two years, and keeps track of around 4,000 species spread across nearly 17,000 population of the planet.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/nearly-60-cent-mammals-extinct-44-yrs
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/deccan-chronicle-telangana
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wwf
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/amazon
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/mammals
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/birds
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wildlife-act-1972
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wildlife