Pygmy tree shrews (Tupaia minor) are distributed on the Malay Peninsula, India, Sumatra, Borneo, and many of the surrounding islands.

Biogeographic Regions: oriental (Native )

Pygmy tree shrews are superficially squirrel-like in appearance, but they can be distinguished from squirrels by their long, pointed snouts and lack of long, black vibrissae. The genus Tupaia can be distinguished from other genera of tree shrews by several external characters. The tail is evenly covered by long hair, the upper section of the ear is larger than the lower lobe, and the hairless section on top of the nose is cut squarely across.

Tupaia minor is characterized by golden brown pelage on the back and limbs, and the underparts vary in color from white to a light cream color. Claws on hands and feet are sharp and moderately curved, allowing for climbing. Pygmy tree shrews move in a semiplantigrade posture. This posture allows a tree shrew to keep its center of gravity close to the tree upon which it is climbing. While grasping on to branches, the pollex and hallux of T. minor become divergent from the other digits. This is an adaptation to arboreal life.

Tupaia minor has an average mass of 60 g and an average head and body length of 124 mm.

Range mass: 50 to 70 g.

Average length: 124 mm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes alike

• Terrestrial

Tupaia minor is found in tropical forests below elevations of 1,000 m. Although it is primarily an arboreal species¸ it has been observed and trapped in both canopy and terrestrial habitats.

Range elevation: 1,000 (high) m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: forest ; rainforest

The digestive tract of T. minor is comprised of a small, simplified stomach, a long, narrow small intestine, a narrow pouch-like cecum, and a smooth large intestine. The gut of T. minor lacks the plant fermentation microorganisms needed to digest plant cell walls. The through time for digested materials ranges from 20 minutes to 45 minutes.

Tupaia minor is omnivorous. Its diet is comprised of a wide variety of invertebrates (including insects and worms) and fruit.

The method of processing fruit for ingestion is dependent on the size and rigidity of the item. Captive observations showed that small fruit is placed into the mouth and chewed. The skin and seeds are ejected from the mouth, and juice and soft pulp are ingested. Ejection of inedible items is accomplished with the help of a forepaw or the tongue. Observations of T. minor in the wild differ slightly. Wild individuals very rarely eject seeds. Fruit that is firm and larger than the gape is often problematic. The weak jaw and procumbent incisors of these animals inhibit their ability to bite off whole chunks from tough fruits. Thus, large or tough fruit is either chewed in the side of the mouth, or licked vigorously. Wild tupaiids tend to concentrate their frugivory on soft fruits that they can handle efficiently.

Animal Foods: insects; terrestrial non-insect arthropods; terrestrial worms

Plant Foods: fruit

Primary Diet: omnivore

It has been suggested that T. minor may play a role as a seed disperser for several Ficus fig species.

Ecosystem Impact: disperses seeds

Predation on members of the genus Tupaia undoubtedly occurs, although details on predatory interactions are lacking in the literature. These smallish mammals are likely prey for snakes, larger mammals, and raptors.

Communication in these mammals has not been extensively documented. Members of the genus Tupaia are known to scent mark their territories with secretions from glands as well as with urine. Because they are diurnal, visual cues are likely to be important in communication. Most mammals also use vocal and tactile communication, especially when mating.

Communication Channels: visual ; tactile ; acoustic ; chemical

Other Communication Modes: scent marks

Perception Channels: visual ; acoustic

To date, all life span knowledge for T. minor is limited to data from captive subjects. In captivity they tend to live a maximum of 9 to 10 years.

Typical lifespan

Status: captivity: 9 to 10 years.

Information on the mating system of this species is not available. However, other species in the genus show either polygyny or polygynandry. In Tupaia glis, a single male rules over a group containing both males and females, although only the dominant male mates with females. Tupaia montana is reported to be slightly more social, with two mutually tolerant males in a group mating with the females. It is not known where in the spectrum of variation T. minor falls, but males of most species in the genus Tupaia form linear dominance heirarchies, which suggests that polygyny of some form may be the rule.

Tupaia minor has a litter size that ranges from 1 to 3 young. Females reach sexual maturity at approximately 46 g, and males reach sexual maturity at approximately 16.3 g. Very little else is known about the reproductive behavior of T. minor. Tupaiids, in general, have a gestation period of 45 to 55 days, and give birth to young weighing from 6 to 10 g. Weaning occurs at approximately 30 days, and sexual maturity is reached at approximately 2 months. After reaching sexual maturity young are forced out of the parental territory.

After giving birth, females become receptive to copulation at once. Breeding in captivity and in the wild can occur year round.

Breeding interval: Breeding can occur every 45 to 55 days.

Breeding season: Breeding may occur year around.

Range number of offspring: 1 to 3.

Range gestation period: 45 to 55 days.

Average weaning age: 30 days.

Average age at sexual or reproductive maturity (female): 2 months.

Average age at sexual or reproductive maturity (male): 2 months.

Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous ; post-partum estrous

Average number of offspring: 2.

The rearing strategies of Tupaidea, including T. minor, are somewhat peculiar. Prior to giving birth, a female makes a large nest, consisting of leaves, wood chips, and other assorted building materials, within a fallen tree. This nest provides the young with protection from the elements and predators. The female then gives birth to her young within the nest. The young are born naked with their ears and eyes closed. Within a few minutes of birth, the young take on approximately half their initial body weight in milk. After feeding, the bellies of the young become distended from the body. The mother then leaves the nest and only returns every 48 hours to feed the young. Each visit lasts only 5 to 10 minutes. The high fat content of Tupaiid milk (~26%) enables the young to maintain a relatively high body temperature (~37 C). The high protein content of the milk (~10%) also helps the young to maintain a rapid growth rate. After approximately 4 weeks the young are able to leave the nest. This occurs with only approximately 90 minutes of parental care from the female. Males are not known to participate in care of the young.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female)

All species of Tupaiidae, including T. minor, are listed on Appendix II of CITES. It is thought that this designation was a result of the entire order Primates being added to the appendix in 1975. At that time the order still included Tupaiidae.

The largest problem facing these animals is human encroachment into tropical forests. This encroachment may take many forms, including logging, cultivation, and human habitation. In each case, the result is ultimately the same: habitat destruction and fragmentation.

In 1995, the IUCN published the Eurasian Insectivores and Tree Shrews: Status Survey and Conservation Action Plan. This plan outlines the status and conservation needs of tree shrews in Southeast Asia. A digital version of this plan can be obtained at:   http://members.vienna.at/shrew/itsesAP95-cover.html.

US Federal List: no special status

CITES: appendix ii

IUCN Red List of Threatened Species: least concern

These tree shrews are not known to have a negative effect on human economies.

These forest animals are not known to have any positive economic importance on humans.