- “Primates In Peril: The world’s 25 most endangered primates 2018-2020” is the tenth iteration of a report issued every two years documenting the primate species from across the globe that are facing the most severe threats of extinction.
- The report finds that the Tapanuli orangutan is one of the world’s most imperiled primates largely due to the impacts of human activities, and that it is hardly alone in that respect: Nearly 70 percent of the 704 known primate species and subspecies in the world are considered threatened; more than 40 percent are listed as Critically Endangered or Endangered.
- Many species are, like the Tapanuli orangutan, down to just a few hundred individuals or less. The Skywalker hoolock gibbon, for instance, was only elevated to full species status by scientists in 2017 and makes it first appearance on the list of the 25 most endangered primates this year because there are less than 150 left in the wild.
When the Tapanuli orangutan was discovered in 2017 in the rainforests of Sumatra, Indonesia, it became the eighth known species of great ape in the world (including humans). The last time a new great ape species was described to science was when the bonobo was found in the Democratic Republic of the Congo in 1929.
From the moment the Tapanuli orangutan’s existence was finally acknowledged by humans, however, its continued existence has been in grave peril thanks to human activities like conversion of the orangutan’s forest habitat to agricultural land and additional deforestation and forest degradation caused by construction of a hydroelectric dam within its range. Interactions with humans often leave the orangutans wounded or dead. The species is listed as Critically Endangered on the IUCN Red List.
It is believed that there may be fewer than 800 Tapanuli orangutans left in the wild, making it one of the most endangered primates in the world, according to a new report released by the Bristol Zoological Society (BZS), the Primate Specialist Group of the International Union for Conservation of Nature (IUCN)’s Species Survival Commission (SSC), the International Primatological Society (IPS), and Global Wildlife Conservation (GWC).
“Primates In Peril: The world’s 25 most endangered primates 2018-2020” is the tenth iteration of a report issued every two years documenting the primate species from across the globe that are facing the most severe threats of extinction. It finds that the Tapanuli orangutan is one of the world’s most imperiled primates largely due to the impacts of human activities, and that it is hardly alone in that respect: Nearly 70 percent of the 704 known primate species and subspecies in the world are considered threatened; more than 40 percent are listed as Critically Endangered or Endangered. The list includes seven primate species from Africa, seven from Asia, six from the Neotropics, and five from Madagascar.
“The inclusion of the critically endangered Tapanuli orangutan on the official list of the world’s most endangered primates is not surprising given the existing threats to its small population, but this underscores a tremendous opportunity,” Dirck Byler, GWC’s great ape conservation director and vice chair for the IUCN SSC’s Primate Specialist Group’s Section on Great Apes, said in a statement. “As the home of the Tapanuli orangutan and two other orangutan species, Indonesia has the chance now to become a leader in great ape conservation by implementing the kinds of measures that will not only protect this special animal and its habitat, but that has the potential to positively impact local economies and livelihoods through ecotourism.”
Many species are, like the Tapanuli orangutan, down to just a few hundred individuals or less. The Skywalker hoolock gibbon, for instance, was only elevated to full species status by scientists in 2017 and makes it first appearance on the list of the 25 most endangered primates this year because there are less than 150 in the wild. “Agricultural encroachment, commercial logging, habitat fragmentation and isolation, and hunting (for bushmeat and pet trade)” are cited in the report as “major threats” to the gibbons, which are found in the forests of the Gaoligong Mountains on the border between southwest China and northern Myanmar.
There are thought to be fewer than 2,000 roloway monkeys remaining in the wild, though the Critically Endangered species could once be found throughout many of the tropical forests of Ghana and the Ivory Coast. “Destruction and degradation of their habitat and relentless hunting for the bushmeat trade have reduced their population to small, isolated pockets,” the report states.
In some cases, there are just dozens of a particular species left. The golden-headed langur is on the brink of extinction with just 50-60 individuals remaining on the island of Cat Ba off northern Vietnam, the species’ only known range. “Hunting has been identified as the sole cause for the dramatic and rapid population decline from an estimated 2,400–2,700 in the 1960s to approximately 50 individuals by 2000,” per the report. “The langurs were poached mainly for trade in traditional medicines and for sport.”
Aside from the Tapanuli orangutan and the Skywalker hoolock gibbon, six other species made the list for the first time: the Bemanasy mouse lemur in Madagascar, the buffy tufted-ear marmoset in Brazil, the Ecuadorian white-fronted capuchin (actually found in Peru and Ecuador), the Olalla brothers’ titi monkey in Bolivia, the pied tamarin in Brazil, and the western chimpanzee in West Africa.
There are four other species included in the list that did not appear on the last list: the Rondo dwarf galago, the kipunji, the Tana River red colobus, and the indri, but these species were added back to the list after having previously been removed.
About 12 species that appeared on the previous list were removed from the current list, though the report’s authors note that these changes “were not [made] because the situation of the twelve species that were dropped has improved. In some cases, the situation has in fact worsened. By making these changes we intend rather to highlight other, closely related species enduring equally bleak prospects for their survival.”
“This report reveals the bleak prospects of some of the world’s most incredible animals. Some are well-known and others barely studied, but all are in danger of extinction from the relentless destruction of their habitats, illegal wildlife trade and commercial bushmeat hunting,” Christoph Schwitzer said in a statement. Schwitzer is the chief zoological officer at BZS and also serves as the IUCN’s red list authority coordinator for the SSC Primate Specialist Group.
“Despite this, I still have hope that it is not too late. There is an unprecedented level of interest in world environmental issues, particularly among the younger generation, many of whom are more inspired, passionate and motivated than ever before to do their part to help make a difference. It is this kind of support, combined with effective conservation action, which is vital if we are to avoid losing these wonderful and charismatic animals forever.”
• Schwitzer, C., Mittermeier, R.A., Rylands, A.B., Chiozza, F., Williamson, E.A., Byler, D., Wich, S., Humle, T., Johnson, C., Mynott, H., and McCabe, G. (eds.). (2019). Primates in Peril: The World’s 25 Most Endangered Primates 2018–2020. IUCN SSC Primate Specialist Group, International Primatological Society, Global Wildlife Conservation, and Bristol Zoological Society, Washington, DC.
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