Tupaiidae - Tree Shrew Family
There is a single family in the order Scandentia, containing approximately 16 species of tree shrew, which live in the forests of eastern Asia, including Borneo and the Philippines. These biologically interesting, but visually undistinguished, mammals have affinities with the order Insectivora, because of their shrewlike appearance, and with the order Primates because of their complex, convoluted brains.
They have been included in both of these orders. Most modern zoologists agree, however, that tree shrews should be placed in a distinct order so that their uniqueness is emphasized, rather than hidden in a large, diverse order. Until much more is known of their biology, tree shrews will remain an enigma.
Tree shrews resemble slim, long-nosed squirrels in general appearance, and their ears are squirrellike in shape and relative size. Their feet are modified for an arboreal existence, having naked soles equipped with knobbly pads, which provide tree shrews with a superb ability to cling to branches. This ability is enhanced by the presence of long flexible digits, with sharp, curved claws. The 16 species range from 4 to 8 1/2 in (10 to 22 cm) in body length, with tails of З 1/2 to 8 3/4 in (9 to 22.5 cm). They run rapidly through the forest canopy, and most are active in the daytime, searching for insects and fruit to consume. They drink frequently and are also fond of bathing.
Despite the name, tree shrews are not exclusively arboreal, and many species spend a good deal of time on the ground. Their senses of smell, sight and hearing are good. Tree shrews usually live in pairs, and males, particularly, are aggressive toward one another. The borders of a pair’s territory are marked with urine and glandular secretions.
There are between 1 and 4 young in a litter, but most usually only 1 or 2. The babies are born in a separate nest separate from the adults’ normal sleeping quarters. The female visits her young only once a day or even every other day. The young are able to take sufficient milk in a short period to sustain them during her absences. Males and females look similar, but males are usually larger.
Tree shrews bear a close resemblance to fossils of the earliest mammals, so it may be assumed that the first true mammals looked, and possibly behaved, like these animals.
Lesser tree shrew
This is the smallest of 11 species of tree shrew from the genus Tupaia. These tree shrews do indeed resemble squirrels, with their long, bushy tails. Unlike most other species of small mammal, they are active throughout the day, though they also have short rests at regular intervals.
Lesser tree shrews' fur colour ranges from a rusty-red colour through dark browns to grey. They have squirrel-like bushy tails and sharp claws.
Their main predators are eagles. Tree shrews are inquisitive, and are constantly searching in holes and crevices for food. Like squirrels, they hold their food in their front paws and eat while sitting on their haunches. Although they are called tree shrews and are capable climbers, they spend a lot of time on the ground or in the branches of bushes.
Tree shrews are highly territorial, with males defending an area of just over 1 ha (2.5 acres), which covers the ranges of one or more females. They repel intruders of the same sex by chasing them and making loud squeals of aggression. Tree shrews also make other calls, which include chattering in response to disturbance, and clucking and whistling during courtship and mating.
Distribution: Malaysia, Sumatra and Borneo.
Food: Insects, small vertebrates, fruit, seeds and leaves.
Size: 14 - 23 cm (5.5 - 9 in); 100 - 300 g (0.2 - 0.6 lb).
Maturity: 3 months. Breeding 1 - 3 young.
Life span: 12 years.
Indian tree shrew
Walter Elliot, an English civil servant based in Madras during the mid-19th century, was the first person to describe this species, hence its Latin name. However, very little has been learned about it since then, even though it seems to occur over much of southern India.
The Madras tree shrew is a squirrellike creature, which is similar in most aspects to the tree shrews of the Tupaia genus. It is identified, however, by its larger ears, heavier snout and the pale stripe on each shoulder.
Unlike other species of tree shrew, this species is rarely found in close proximity to human dwellings. It has been seen in the dry deciduous forests on India’s Deccan Plateau, and presumably has very similar habits to other tree shrews. It has also been found living in rocky upland habitats, without trees, at altitudes of 1,400 m (4,600 ft).
The Indian tree shrew, also sometimes called the Madras tree shrew, can be distinguished from other species of tree shrew living in India by its larger and more thickly haired ears.
The Indian tree shrew spends a large part of the day searching for food and then returns to a hole among rocks before nightfall, where it shelters until dawn. These shrews appear to be solitary animals, almost always foraging alone and rarely, if ever, sharing shelters. However, occasionally small groups of three or four individuals have been observed playing together for short periods. Little is known about its breeding habits, but they are probably similar to those of the Tupaia tree shrews.
Distribution: India, south of the Ganges River.
Food: Insects, earthworms and fruit.
Size: 17 - 20 cm (7 - 8 in); 160 g (0.3 lb).
Maturity: 3 months.
Breeding: 1 - 3 young born in related species.
Life span: Unknown.
Bornean Smooth-tailed Tree Shrew
This species is the smallest of the tree shrews. It is distinguished by its smooth, short-haired tail, which ends in a point. Its body fur, too, is short and close with a dark reddish-brown on the back and lighter orange-buff on the underparts. More arboreal than the other members of its family, it finds much of its insect food on the lower branches of trees. Its breeding habits are not known.
Habitat: Montane forest above 3,000 ft (900 m)
Size: Body: 4 1/2 - 6 in (11 - 15 cm); Tail: 3 1/2 5 1/2 in (9 - 14 cm).
Feather-tailed Tree Shrew
This tree shrew is easily identified by its unusual tail, which is naked for much of its length, but has tufts of hair on each side of the terminal portion, making it resemble a feather. Its ears, which are large and membranous, stand away from the head. Its hands and feet are larger, relative to body size, than those of other tree shrews. The feather-tailed tree shrew is thought to be nocturnal. It spends much of its life in trees and is a good climber, using its tail for balance and support and spreading its toes and fingers wide for grip. Insects, fruit and some lizards are its main foods.
Feather-tailed tree shrews nest in holes in trees or branches, well off the ground, but their breeding habits are not known. They generally live in pairs.
Range: Malaysia, Sumatra, Borneo.
Habitat: Rain forest.
Size: Body: 4 3/4 - 5 1/2 in (12 - 14 cm) Tail: 6 1/4 - 7 in (16 - 18 cm).