Common Treeshrew

Overview

The Common Treeshrew (Tupaia glis) is an athletic, squirrel-like, and evolutionary prominent placental mammal native to the lush, steaming lowland rainforests and plantations of Southeast Asia. Belonging to the ancient order Scandentia, this energetic forest dweller is renowned across evolutionary anthropology as one of the closest living non-primate relatives to primates, sharing a common ancestor with early proto-primates roughly 65 million years ago. Despite its misleading name, it is neither a true shrew nor exclusively arboreal, moving with frantic, lightning-fast agility between tree branches and the forest floor.

Dressed in a rich, grizzled reddish-brown coat with an olive-flecked dorsal sheen and a bushy tail, Tupaia glis is famous in animal physiology for two jaw-dropping biological superpowers. First, it possesses an extraordinary metabolic resistance to alcohol: it regularly drinks naturally fermented floral nectar from the Bertam palm (Eugeissona tristis) that contains up to 3.8% alcohol—the equivalent of beer—without ever showing signs of drunkenness or liver damage. Second, it possesses a mutated TRPV1 pain receptor that allows it to eat blistering-hot, capsaicin-packed chili peppers with complete indifference, making it a foundational model in neurological and biomedical research.

Biology and Physical Characteristics

Morphologically, Tupaia glis possesses a slender, muscular body, a pointed, mobile snout, and large, dark, protruding eyes that provide a wide stereoscopic field of view. Unlike nocturnal tree dwellers, its retina is packed with cone photoreceptors, providing sharp diurnal color vision. Its brain is exceptionally large relative to its body mass—higher even than a human’s on a pure weight-to-body percentage basis. Its feet are armed with five nimble, elongated digits terminating in sharp, curved claws that provide an unshakeable grip on slick bark, while its ankle joints can rotate up to 180 degrees, allowing the treeshrew to scramble down tree trunks head-first with effortless stability. Its dental formula includes sharp, piercing canines and tribosphenic molars designed to crack hard beetle chitin and slice through wild figs.

Behavior and Ecology

Behaviorally, common treeshrews are strictly diurnal, hyperactive, and highly territorial, spending their daylight hours in continuous foraging runs along rotting logs, low branches, and leaf litter. Pairs are monogamous and maintain exclusive territories marked with musky secretions from specialized sternal and throat scent glands, which they rub vigorously against branches. Their maternal care system is one of the most hands-off and bizarre in the mammalian world, known as ‘absentee parental care’: the female builds two separate nests—one for herself and one for her pups. After giving birth to one to three naked young, the mother visits the nursery nest only once every 48 hours for a mere five to ten minutes, providing an ultra-rich, protein-dense milk before leaving her pups completely unattended for the next two days.

Conservation and Human Impact

The Common Treeshrew is classified as Least Concern on the IUCN Red List of Threatened Species, supported by its wide geographic distribution across the Sundaland region, high reproductive turnover, and remarkable tolerance of disturbed secondary forests and oil palm plantations. Because it is highly adaptable, it frequently thrives in agricultural hedges and suburban gardens where primary forest has been cleared. While localized deforestation for timber and oil palm monocultures has reduced primary forest habitat, the species remains exceptionally abundant throughout its native range in Malaysia and Indonesia.

Interesting Factoid

The common treeshrew can drink naturally fermented palm nectar all night long—drinking the human equivalent of nine glasses of beer every single day—without ever getting drunk, having a hangover, or suffering any liver damage!