Ptilocercus lowiipen-tailed tree shrew

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Geographic Range

The Pentailed tree shrew is found in peninsular Thailand, Malaysia, Sumatra, northern Borneo and nearby small islands (Corbet 1991; Payne 1985).

Habitat

This species has been found in primary and secondary forests, rubber farms, and in houses near forest edges. They are often associated with the palm tree Eugeissona tristis. Pentail Tree Shrews are usually caught 1.5-2 meters off the ground on vines and branches. Specimens have been collected at altitudes from sea level to 2000 meters (Muul and Lim 1971). Nests have been reported in large branches and tree trunks 12-20 meters above the ground (Lim 1967).

Physical Description

Ptilocercus lowii has a typical body length of 130-140 mm, and a tail length of 160-190 mm. The animal's back is gray to light brown, with a white/yellowish belly (Gould 1978). It is easily identified by the plume like hairs on the latter 2/5ths of the tail. The "pen tail" is proximally black, fading to white distally, making the Pentail Tree Shrew easily recognizable. Individuals also frequently have a black eye mask (Clark 1926).

  • Range mass
    40 to 62 g
    1.41 to 2.19 oz
  • Average basal metabolic rate
    0.24 W
    AnAge

Reproduction

Very little life history work has been done on Ptilocercus lowii, as it is rare and difficult to capture (compared to other tupaiids). However, they have two pairs of nipples, suggesting litter sizes of 1 to 4 offspring. Typical tupaiid gestation periods are 45-55 days resulting in the birth of babies weighing about 10 grams (Parker 1989).

Three genera of tupaiids (/Tupaia, Urogale, Lyonogale/) have very unusual mother-offspring relationships. After birth the female will nurse the young, who take on about 50% of their initial body weight (5 grams) in milk. The stuffed babies are then left alone, the mother returning only every 48 hours to perform the same mass feeding session. This milk is unusually high in fat content (~26%) which allows the young to maintain high body temperatures (37 C) without the aid of their mother's warmth. The milk is also high in protein (10%) and the babies are ready to leave the nest in only 4 weeks. The mother also leaves a scent at the nest that deters the father or other conspecifics from entering. This avoidance behavior is so strong that food items sprayed with the scent are not touched by other individuals (Parker 1989).

Because captive breeding has not been done with Ptilocercus, whether this strange parenting method characterizes the Pentail Tree Shrew is unknown.

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Average number of offspring
    2
    AnAge

Lifespan/Longevity

Behavior

Ptilocercus lowii is the only nocturnal tupaiid. Quite lethargic during the day, they will often confront a human disturbance by turning on their back exposing the belly, hissing loudly and gaping widely, often urinating and defecating. This is quite different from a disturbance at night, when the now energetic animal will quickly run away from its disturber (Gould 1978). Communal nesting is suspected as individuals in nature are often found in nests in groups of 2-5 (Lim 1967). This behavior has also been noticed in captives, where individuals will sleep together after a period of contact (Gould 1978). A study done on P. lowii by Whittow and Gould (1976) showed that both oxygen consumption and body temperature dropped significantly during the day while sleeping. This drop in metabolic rate may be associated with energy conservation, and possibly the communal nesting found in the wild and captivity. Like other tupaiids, Ptilocercus lowii can walk on the underside of branches (Gould 1978). Their tails are extremely sensitive to the touch, and are frequently used in displays like "tail wagging" (a pendulum-like motion) after aggressive encounters, or are held up straight showing excitement (Gould 1978).

Nests are constructed inside trees, lined with dried leaves, twigs, fibers of soft woods (Lim 1967) and are about 3 inches in diameter and 18 inches long (Lyon 1915).

Communication and Perception

Food Habits

Like most Tupaiids, Ptilocercus lowii is an omnivore. They have been observed eating bananas, grapes, crickets, and grasshoppers (Gould 1978). One study of stomach contents found black ants, cockroaches, beetles, earwigs, cicadas, leaf insects, and even a young forest gecko (/Gymnodactylus mamaorat/) (Lim 1967). This wide variety in diet suggests that the Pentail Tree Shrew is rather adept at capturing food (Gould 1978).

Economic Importance for Humans: Positive

Ptilocercus lowii is of no economic importance to humans.

Economic Importance for Humans: Negative

Ptilocercus lowii is of no economic importance to humans.

Conservation Status

The Pentail Tree Shrew is currently on Appendix II of CITES.

A 1995 publication by the IUCN called Eurasian Insectivores and Tree Shrews outlines current plans for Southeast Asian conservation involving Tree Shrews. A partially digital version is available at: http://members.vienna.at/shrew/itsesAP95-cover.html. The section involving Tree Shrews has not yet been digitized.

However the basic problem facing the tree shrew is slash-and-burn clearing of tropical forests for cultivation and human use. As with most threatened species, habitat fragmentation and destruction pose a strong threat to this animal.

Other Comments

The phylogenetic placement of the family Tupaiidae has long been controversial. In the past, tree shrews have been varyingly placed in the Order Insectivora or in the Order Primates. Most modern classifications place the tree shrews in their own order, the Scandentia, part of the larger Archontan clade along with Primates, Chiroptera, and Dermoptera. Ptilocercus is the sole member of the subfamily Ptilocercinae.

Contributors

Sean Askay (author), University of California, Berkeley, James Patton (editor), University of California, Berkeley.

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

References

Clarke, W. 1926. On the Anatomy of the Pen-tailed Tree-shrew -Ptilocercus lowi-. Proc. Zool. Soc. London: 1179-1309.

Corbet, G., J. Hill. 1992. The Mammals of the Indomalaysian Region: a systematic review. New York: Natural History Museum Publications, Oxford Univ. Press.

Gould, E. 1978. The behavior of the Moonrat -Echinosorex gymnurus- (Erinaceidae) and the Pentailed Shrew -Ptilocercus lowi- (Tupaiidae) with Comments on the Behavior of other Insectivora. Z. Teirpsychol., 48: 1-27.

Lim, B. 1967. Note on the food habits of -Ptilocercus lowi- Gray (Pentail tree-shrew) and -Echinosorex gymnurus- (Raffles) (Moonrat) in Malaya with remarks on. Proc. J. Zool. London, 152: 375-379.

Lyon, M. 1915. Tree Shrews: An account of the mammalian family Tupaiidae. Proc. US National Museum, 45: 1-183.

Muul, I., B. Lim. 1971. New locality records for some mammals of West Malaysia. J. Mammology, 52(2): 430-437.

Parker, S. 1989. Grzimek's Encyclopedia of Mammals. San Francisco: McGraw-Hill Publishing Co..

Payne, P., C. Francis. 1985. A Fielf Guide to the Mammals of Borneo. Kuala Lumpur: The Sabah Society and World Wildlife Fund Malaysia.

Stone, D. 1995. "Eurasian Insectivores and Tree Shrews: Status Survey and Conservation Action Plan" (On-line). Accessed November 1999 at http://members.vienna.at/shrew/itsesAP95-cover.html.

Whittow, G., E. Gould. 1976. Body Temperature and oxygen consumption of the Pentail Tree Shrew -Ptilocercus lowi-. J. Mammalogy, 54(4): 754-756.