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Congress Overview Programme Schedule
Press Centre 25 Most Endangered Species

21st Congress International Primatological Society


Evening Discussion

The IUCN/SSC Primate Specialist Group and CI have joined forces to present and review the list and content of the World's 25 Most Endangered Primates every two years through an open meeting at the IPS Congresses. The Top 25 list of the world’s most endangered primates is a conservation outreach tool developed by the IUCN/SSC Primate Specialist Group. Originally compiled to mark the turn of the millennium, the Top 25 list is now revised on a biannual basis with substantial input from field primatologists, working at special sessions convened at each Congress of the International Primatological Society.

Drawn from the disturbingly large pool of Critically Endangered primates, the Top 25 list highlights representative taxa to illustrate the overwhelming threats to primate diversity. Our aim is not to offer a prioritized list for conservation triage, but rather to provide examples of the fragile state of the world’s rarest primate taxa, carefully selected to illustrate the chief threats and the geographic regions where their situation appears most dire. Our target audience is the educated public of all the world – most especially of those nations where primates exist, or where policies and patterns of consumption feed the countless threats. The Top 25 list is thus a media interface between those who are most aware of the primate crisis, and those who by their collective action are best able to address it.

The frequent revision of the Top 25 list allows the PSG to maintain its emphasis on those taxa and regions which would most benefit from timely exposure in the media. This is clearly seen by the recent awareness of the many endangered taxa surviving in Vietnam, as well as concentrations of critically imperiled primates in Sri Lanka, eastern Africa, Madagascar and southeastern Brazil. Madagascar and Vietnam together contribute eight taxa, or 32% of the total list – drawing singular attention to the immediate need for conservation action in these two countries. And the current version of the list includes one primate taxon, the Mt. Rungwe galago, which has not even been formally described – highlighting all too sharply how some species, even primates, may vanish before we were fully aware that they lived at all.

The Top 25 list will again be revised at the 2006 Congress of the IPS in Uganda, and we encourage all primatologists to attend and contribute their observations from the field – for only with fresh information will the list be at its most effective. There will be an evening discussion at the congress venue on tuesday, June 27th in Kidepo Hall (please note that a room change is possible) beginning at 8:00pm. Additional background information for this discussion is available from the following link: 25 Most Endangered Primates 1MB.

The following are currently on the list of the World’s Top 25 Most Endangered Primates.


Prolemur simus - Greater bamboo lemur - Madagascar

Eulemur albocollaris - White-collared lemur - Madagascar

Propithecus candidus - Silky sifaka - Madagascar

Propithecus perrieri - Perrier’s sifaka - Madagascar


Galagoides sp - (undescribed) - SW Tanzania (Mt. Rungwe galago)

Procolobus pennantii pennantii - Pennant’s red colobus - Equatorial Guinea (Bioko Is)

Procolobus rufomitratus - Tana River red colobus - Kenya

Cercocebus atys lunulatus - White-naped mangabey - Côte d’Ivoire, Ghana

Cercocebus sanjei - Sanje mangabey - Tanzania

Gorilla beringei - Eastern gorillas - Rwanda, Uganda, DRC

Gorilla gorilla diehli - Cross River gorilla - Cameroon, Nigeria


Loris lydekkerianus nycticeboides - Horton Plains slender loris, Ceylon mountain slender loris - Sri Lanka

Simias concolor - Pig-tailed langur, Pagai pig-tailed snub-nosed monkey, Siberut pig-tailed snub-nosed monkey - Indonesia (Mentawai Is)

Presbytis hosei canicrus - Miller’s grizzled surili - Indonesia (E. Central Kalimantan)

Trachypithecus delacouri - Delacour’s langur, white-rumped black leaf monkey - Vietnam

Trachypithecus poliocephalus poliocephalus - Golden-headed langur, Tonkin hooded black langur - Vietnam (Cat Ba Island)

Semnopithecus vetulus nestor - Western purple-faced langur - W. Sri Lanka

Pygathrix nemaeus cinerea - Grey-shanked douc - Vietnam

Rhinopithecus avunculus - Tonkin snub-nosed monkey - Vietnam

Nomascus nasutus hainanus - Hainan black-crested gibbon - China (Hainan Is.)

Pongo abelii - Sumatran orangutan - N. Sumatra, Indonesia


Leontopithecus caissara - Black-faced lion tamarin - Brazil

Cebus xanthosternos - Buffy-headed tufted capuchin - Brazil

Ateles hybridus brunneus - Brown spider monkey - Colombia

Brachyteles hypoxanthus - Northern muriqui - Brazil

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