Horsfield's treeshrew, also called the Javan treeshrew, is endemic to the Indonesian islands of Sumatra, Bali, Java and Nias, where it inhabits foremost primary forest. It was first described by Thomas Horsfield in 1822. Several subspecies have been proposed based on colour variation, but colour is an unreliable distinguishing character (Wikipedia, general species account).
It eats fruits and insects, mostly arthropods, and so spreads plant seeds and controls insects (Wikipedia, general species account).
Description: Wildlife of Sumatra guide, Wildlife of Everywhere (wildlifeofeverywhere.com); general species information paraphrased from Wikipedia (CC BY-SA)
Mammals of the World