The latest update of the IUCN Red list of threatened species is hot off the press. One of this year’s additions to the list is the Siau Island Tarsier (Tarsius tumpara) which is classified as Critically Endangered (this is the highest threat category that can be assigned to a species before extinction). This unique primate is restricted to a very small area, and its population is suspected to have declined by 80%. The Siau Tarsier is under threat from being collected for food and by Mt. Karengentangm, an active volcano which dominates more than half of its range. These circumstances have led the IUCN Species Survival Commission Primate Specialist Group to name it one of the 25 most threatened primates in the world.
In our current phylogeny this genus, Tarsius, is represented by 5 species: bancanus, dentatus, pelegensis, sangirensis and tarsier. They are all EDGE species despite having lower levels of endangerment than the Sian Island Tarsier. In light of their ranking and the new species’ critical status it is highly likely that the Sian Island Tarsier will enter EDGE’s top 100 mammal list in the near future.
Another interesting addition to this year’s Red List is the Siau Island Tarsier’s cousin, the recently discovered Wallace’s Tarsier (Tarsius wallacei), which occurs in the Isthmus of Palu and a small area southwest of Palu, in Central Sulawesi, Indonesia. The two populations are isolated and threatened by habitat loss and degradation which result from conversion of land to crash crop plantations. Wallace’s Tarsier was first described in 2010 and additional research into the population status is needed. Since not enough information is known about Wallace’s Tarsier it cannot be assigned to any category other than Data Deficient.
Given Wallace’s Tarsier evolutionary distinctiveness it is probably a potential EDGE species. This means that if it is found to be threatened (Globally Endangered) there is a high probability it will become an EDGE species. Other potential EDGE mammals which are currently listed as Data Deficient include: the Jentink’s dormouse, the four-toed mole tenrec, and the felou gundi, a guinea pig-like rodent which has modified toes for grooming.
“It is extremely important that we keep pushing forward with surveys of little-known species, as without adequate data, we cannot determine their risk of extinction and therefore cannot develop or implement effective conservation actions which could prevent the species from disappearing altogether,” says Jane Smart, Director, IUCN’s Global Species Programme.