Tupaia tana
large tree shrew

Large tree shrews (Tupaia tana) are found on the island of Borneo, including the countries of Brunei Darussalam, Indonesia, and Malaysia. ("Tupaia tana", 2006; Emmons, 2000b)

Large tree shrews are the most terrestrial of all tree shrew (Scandentia) species. They live part of their lives in the trees of tropical rainforests, swamp forests, and secondary growth forests, but spend most of their time on the forest floor, which is their primary location for foraging. Large tree shrews have been found at elevations of 1000 m above sea level but most often occur in lowland forest areas. ("Ecoregions containing Large Tree Shrew", 2006; Emmons, 2000b)

On average, Tupaia tana weighs 198 grams and has a head and body length of 22 centimeters. Tupaia tana has an elongated snout that is longer than that found in other tree shrew species. The eyes are large and without lashes and the ears are hairless. The fur of large tree shrews is dark brown on the dorsal side and reddish-orange on the ventral side of the animal. Yellow stripes are present on each shoulder and a distinct black stripe is present down the midline of the back. The tail is bushy and quite short in comparison to the length of the rest of the body and in comparison to the tails of other tree shrews. The color of the tail varies between orange, yellow, and red depending on geographic location. As in most scansorial mammals, large tree shrews possess elongated claws used to hold on to branches and for digging. Canines are well-developed, but the teeth in general are non-specialized. Males and females are similar in size and appearance. ("Treeshrews", 2003; Emmons, 2000a; Emmons, 2000b; Sargis, 2001)

Tree shrews have been found to live between 10 and 14 years in the wild. (Primmer, 2002)

Tupaia tana is a diurnal, solitary species, and of all members of the family Tupaiidae, Tupaia tana is the most terrestrial. In general, individuals are found in the trees scanning the area for possible danger for relatively short periods of time. Large tree shrews are also among the least active of the tree shrews, resting occasionally throughout the day. Females are more active than males. Most of the large tree shrew's day (like most tree shrews) is spent foraging for food. Populations are dynamic, in that membership changes throughout the year. (Emmons, 2000a; Emmons, 2000b)

Home Range

All individuals establish a territory that averages 300 to 600 square meters, with the male’s territory generally larger than that of females. Territory is marked by odor excreted from chin and anal scent glands. In Tupaia tana, territories more frequently overlap between individuals than in other tree shrew species. (Emmons, 2000a; Emmons, 2000b)

Large tree shrews have sensitive hearing. They also have large eyes that permit acute day vision, but are quite poor for night vision. There are no vibrissae on the face. The olfactory system is the most important in sensing the environment and for recognition. Young rarely vocalize, instead they use odor to identify their mother. Adults are not very vocal but chatter when alarmed from a close range and emit whistles when alarmed from a long distance. (Emmons, 2000b)

Tree shrews feed on a variety of foods including beetles, ants, spiders, cockroaches, crickets, and other invertebrates. They prefer earthworms, centipedes, millipedes, and beetle larvae. Foraging takes place almost exclusively on the ground. Tupaia tana is somewhat unique in that it finds much of its food under the first layer of soil by using its claws to dig and its snout to search. Fruit, when readily available, seems to be eaten more than previously thought but is still probably less than 30% of the diet. Fruit from fig trees is a popular choice. Tupaia tana is a fairly slow forager and has been known to return to the same area for several consecutive days to find food. Much foraging is done near a river or stream. Large tree shrews have a simple digestive system that lacks a caecum, consistent with their mainly arthropod diet. When eating fruit, individuals usually suck the juices out of the fruit without eating the pulp. They are known for their fiber-spitting behavior in which they spit out indigestible seeds and plant parts that they may accidentally ingest. Large tree shrews occasionally feed on small mammals and lizards. Maximum weight is most commonly achieved in September and November for females and in November and December for males. ("Treeshrews", 2003; Emmons, 2000b; Shanahan and Compton, 2000)

Tree shrews have many potential predators. Cats like marbled cats, leopard cats, and clouded leopards are among the only predators of adult tree shrews. Nestlings are more vulnerable. Birds of prey are the biggest threat to young. One study showed that yellow-throated martens were the most numerous predators during the day. Reptiles, civets, mongooses, and invertebrates, such as ants, also feed on nestlings. The nests of Tupaia tana are poorly hidden compared to those of other tree shrew species but are practically odorless, which makes them much harder for potential predators to find. Also, adult tree shrews vary the routes they take to their nest and are very cautious when entering and leaving their nest; this helps them to avoid predators and keep their nest site a secret. (Emmons, 2000b)

Tupaia tana contributes as a seed disperser, helping to regenerate fruiting trees in the forests they inhabit. (Shanahan and Compton, 2000)

There are no known adverse effects of Tupaia tana on humans.

Large tree shrews help to maintain tropical, lowland forest regeneration through dispersing seeds.

The conservation status of Tupaia tana was last evaluated in 1996 by the Insectivore Specialist Group of the IUCN, and it was decided that populations were stable at that time. ("Tupaia tana", 2006)

Tupaia tana means ‘ground squirrel’ in Bahasa Indonesian. Recent research suggests that tree shrews share a common ancestor with primates and could help in piecing together the evolutionary history of Homo sapiens. ("Treeshrews", 2003; Emmons, 2000a)