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.
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.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
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.
US Federal List: no special status
CITES: appendix ii
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
There are no known adverse effects of Tupaia tana on humans.
Large tree shrews help to maintain tropical, lowland forest regeneration through dispersing seeds.
Tupaia tana contributes as a seed disperser, helping to regenerate fruiting trees in the forests they inhabit.
Ecosystem Impact: disperses seeds
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.
Animal Foods: mammals; reptiles; insects; terrestrial non-insect arthropods; terrestrial worms
Plant Foods: fruit
Primary Diet: carnivore (Eats non-insect arthropods); omnivore
Large tree shrews (Tupaia tana) are found on the island of Borneo, including the countries of Brunei Darussalam, Indonesia, and Malaysia.
Biogeographic Regions: oriental (Native )
Other Geographic Terms: island endemic
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.
Range elevation: 0 to 1000 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: rainforest
Tree shrews have been found to live between 10 and 14 years in the wild.
Status: wild: 10 to 14 years.
Status: captivity: 11.6 years.
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.
Average mass: 198 g.
Average length: 22 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
Average mass: 797 g.
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.
Anti-predator Adaptations: cryptic
Large tree shrews form monogamous pairs, and it has been found that these bonds are “looser” than for most other tree shrews. Males initiate mating behavior and usually mate with the female with which they share the most territory overlap.
Mating System: monogamous
Reproductive maturity for both females and males is reached at around one year of age, although a territory is usually established before this time. Peak breeding occurs between the months of August and November. Spherical nests constructed from woody fibers and surrounded by leaves are built on the ground, or between o.2 and 8 meters above ground in small trees or rotten stumps. Mates seem to not share the same nest. The mother almost always gives birth to two altricial young. The young are weaned after 25 to 33 days.
Breeding interval: Breeding occurs once yearly in Tupaia tana.
Breeding season: Breeding occurs from August to November.
Range number of offspring: 1 to 2.
Average number of offspring: 2.
Range weaning age: 25 to 33 days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average number of offspring: 2.2.
All tree shrew species are said to have an “absentee” maternal care system. More observations need to be made, but there is strong evidence that large tree shrews have this kind of parental care system as well. After the young are born, the mother visits the nest every other day usually in the early morning. These encounters last for less than five minutes and it is at these times that the mother nurses her young. Following weaning, the mother calls her young to follow her to a new nest site where the young will continue to live without the mother (she will remain at the initial nest site). The first couple of days after weaning, the mother spends almost all of her time with her young and still invests much of her time with them thereafter. Tupaia tana has a somewhat reversed form of parental care from most other mammals in that there is little care before weaning, but much care after weaning.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female); pre-independence (Provisioning: Female, Protecting: Female); post-independence association with parents; extended period of juvenile learning
Large treeshrews are the most predominantly terrestrial of all treeshrew species. They are usually on the forest floor, the primary location for their foraging, although they spend part of their time in trees. T. tana has been described as mainly terrestrial based on field observations and their morphological traits. Large treeshrews are most abundant in primary tropical rainforest, but are also found in swamp forest and secondary growth forest. T. tana has many potential predators such as the marbled cat, leopard, and clouded leopard.
Tupaia tana is slightly larger than the common treeshrew (T. glis). The dorsal fur is reddish brown, shading to nearly black at the rear. There is a black stripe running from the neck half to two thirds of the way down the back, until it disappears in the darker posterior fur.
The body size measurements of this species are:
The snout is long: the distance from the center of the eye to the tip of the muzzle is more than 37 mm in adults.
Tupaia tana has sensitive hearing and large eyes that give it acute night vision but poor daylight vision.
Their diet consists of earthworms and arthropods such as centipedes, millipedes and beetle larvae, with some fruit. Less favored arthropods include ants, beetles, spiders, cockroaches and crickets.
The average age of reproductive maturity for both males and females is around one year of age. The female almost always gives birth to two altricial young. The fecundity of females is reduced in poor quality territories or during periods of resource scarcity.