Mentawai Islands rain forests
The Mentawai Islands rain forests are a tropical moist broadleaf forest ecoregion in Indonesia. It covers the Mentawai Islands, an archipelago in the Indian Ocean off the west coast of Sumatra. The islands have been separated from Sumatra since the mid-Pleistocene period, and their geographic isolation allowed the evolution of several endemic species, including 17 endemic mammals.
Geography
The ecoregion has an area of 6,513 square kilometers, which includes all the Mentawai Islands, the largest of which are Siberut, Sipura, North Pagai, and South Pagai, as well as Enggano Island further to the southeast. The islands lie 80 to 120 km from the west coast of Sumatra.Climate
The islands have a tropical rainforest climate. Average annual rainfall is approximately 4,500 mm, with an October to March wet season. Temperatures average about 30°C year-round.Flora
The forests have a closed canopy about 36 metres high, with emergent trees rising 45 metres or more. Trees of the dipterocarp family are common canopy and emergent trees. Emergent trees include species of the dipterocarp genera Dipterocarpus and Shorea, and species of Koompassia, Sindora, and Dialium. Canopy trees include species of Mallotus, Knema, Santiria, Bhesa, Eugenia, Baccaurea, Dillenia, Artocarpus, and Horsfieldia.Fauna
There are six endemic primates in the ecoregion – Kloss's gibbon, Mentawai macaque, Siberut macaque, Mentawai langur, Siberut langur, and pig-tailed langur. Other endemic mammals include the Mentawai treeshrew, Sipora flying squirrel, Mentawai long-tailed giant rat, Pagai spiny rat, Mentawai rat, Mentawi flying squirrel, Siberut flying squirrel, and short-headed leaf-nosed bat. Other native mammals include the Asian palm civet and crab-eating macaque.There are over 250 native species of birds on the islands. The Mentawai scops owl is the only known endemic species.