This is the 2018–2020 iteration of the World’s 25 Most Endangered Primates list, drawn up during an open meeting held during the XXVII Congress of the International Primatological Society (IPS), Nairobi, 22 August 2018.
IUCN has updated the species profiles from the 2016–2018 edition for those species remaining on the list and added additional profiles for newly listed species. This publication is a joint eﬀort of the IUCN SSC Primate Specialist Group, the International Primatological Society, Global Wildlife Conservation, and the Bristol Zoological Society.
The list has seven species from Africa, five from Madagascar, seven from Asia, and six from the Neotropics (Appendix: Table 1). Indonesia, Brazil, Ghana and Cote d’Ivoire each have three, Nigeria and Tanzania two, and China, Myanmar, India, Bhutan, Sri Lanka, Vietnam, Argentina, Ecuador, Peru, Mexico, Guatemala, Nicaragua, Honduras, El Salvador, Costa Rica, Panama, Bolivia, Guinea-Bissau, Liberia, Republic of Guinea, Senegal, Sierra Leone, Togo, Benin and Kenya each have one.
Twelve of the primates were not on the previous (2016–2018) list (Appendix: Table 3). Eight of them are listed as among the world’s most endangered primates for the first time. The Rondo dwarf galago, kipunji, Tana River red colobus and indri had already been on previous iterations, but were subsequently removed in favour of other highly threatened species. The 2018–2020 list contains two members each of the genera Piliocolobus and Trachypithecus, thus particularly highlighting the severe threats that large primates are facing in all of the world’s primate habitat regions.
The changes made in this list compared to the previous iteration (2016–2018) were not because the situation of the twelve species that were dropped (Appendix: Table 2) has improved. In some cases, the situation has in fact worsened. By making these changes, the IUCN intends rather to highlight other, closely related species enduring equally bleak prospects for their survival.
During the discussion of the 2018–2020 list at the XXVII Congress of IPS in Nairobi in 2018, a number of other highly threatened primate species were considered for inclusion (page 102). For all of these, the situation in the wild is as precarious as it is for those that finally made it on the list, thus they have been included as ‘Other Species Considered’, a new category in the Top 25 Most Endangered Primates’ series.