Why the Sumatran Islands?

The diminishing lowland and upland rainforests of Sumatra and its surrounding islands, particularly the Mentawi Islands, are home to a very high density of globally threatened small mammal species. The overall small mammal fauna is dominated by squirrels (24 species) and murid rodents (32 species) as well as tree-shrews (8 species). A distinctive feature of this diversity is the large number of globally threatened and Data Deficient flying squirrels and squirrels, such as the Black Flying Squirrel Aeromys tephromelas, Whiskered Flying Squirrel Petinomys genibarbis, Smoky Flying Squirrel Pteromyscus pulverulentus and Fraternal Squirrel Sundasciurus fraterculus. Just two AZE trigger small mammal species are found on Sumatra - the Sipora Flying Squirrel Hylopetes sipora of Sipora Island (west coast of Sumatra) and the Sumatra Water Shrew Chimarrogale sumatrana of Pagar Alam. In terms of eulipotyphlan insectivores, the Vulnerable Dwarf Gymnure Hylomys parvus can be found on the slopes of Mount Kerinci on the west coast of Sumatra.


Between 65% and 80% of Sumatra’s lowland and montane forests have been lost to logging and agriculture – predominantly oil palm plantations. Sumatra is probably losing its forest habitats faster than any other part of Indonesia as, despite legal protection, forest is still being cleared today.
There are also 12 Data Deficient species, about which too little is known to determine their true conservation status according to the IUCN Red List.


As in Borneo, multiple national and international NGOs are working to try to save Sumatra’s remaining forests to benefit both wildlife and people. It is vital that the needs of many tens of globally threatened small mammals are taken into account in these large-scale forest conservation initiatives. This includes NGOs such as WWF, working with major investors to stop or restrict financing of palm oil plantations across Indonesia.
Like many of our Key Regions, Sumatra’s small mammal fauna is poorly known. With 12 Data Deficient species on Sumatra, the priority is to understand more about their distribution and population history, after which we can assess extinction risk. We also need to conduct research to understand more of the ecology of Sumatra’s globally threatened small mammal species, so that effective small mammal-targeted conservation plans may be developed.

Future Plans

The Sumatran Islands form one of the SMSG Key Regions in which we plan to fill international knowledge gaps and develop a regional initiative to support and coordinate in-country research and conservation efforts to protect this unique assemblage of small mammals.
At present, the SMSG is working to organise knowledge-gathering and network-building workshops in our three highest priority Key Regions, through which we seek to forge links and recruit local members to spearhead our efforts to galvanise research and conservation focussed on each region’s small mammal species. Our work in these regions will be used to perfect our methodology for achieving similar goals in all our Key Regions. Eventually, we hope to nurture collaborative networks of local and international conservation professionals in every Key Region, which are committed to the study and protection of each region’s small mammal diversity.
While the SMSG is not currently active on the Sumatran Islands, we plan to turn our attention to this important region as soon as possible. We will continue to monitor the state of this region’s small mammals through the international scientific literature and IUCN Red List.
If you are a professional small mammal ecologist, taxonomist or conservationist working on the Sumatran Islands, please do Contact Us to discuss your work and how the SMSG might help.