Rhinosciurus laticaudatusshrew-faced squirrel

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Geographic Range

The long-nosed squirrel is widely distributed throughout the Malay Peninsula, southern Thailand, Riau Archipelago, Borneo, Tioman, Sumatra, the Natuna Islands, and the Sunda Islands. (Lim 1999; Medway 1969; Nowak 1999; Chasen 1946)

Habitat

Long-nosed squirrels are usually found inhabiting primary and secondary tall forests. They have also been found in the lowlands and hills of Sumatra, Borneo, and intervening islands at elevations as high as 900 meters above sea level. These squirrels forage on the ground and nest in hollow logs. (Chasen 1946; Francis 1985; Lekagul 1977; Medway 1969; Nowak 1999)

  • Range elevation
    0 to 900 m
    0.00 to 2952.76 ft

Physical Description

The length of the head and the body of R. laticaudatus is approximately 185 to 242 mm, while the tail is 95 to 150 mm. The hind feet are usually 42 to 49 mm. Rhinosciurus laticaudatus has an interesting pelage. The coloring of the head and dorsal fur can vary from reddish brown to a grizzled olive brown. The sides and underparts of this squirrel are white or yellowish white. The short, bushy tail is often held upwards and has gray fur with white tips.

The most defining characteristic of Rhinosciurus is its elongated rostrum. Its snout is longer than that of any other Thai squirrel. The lower incisors are long and slender, while the upper incisors are tiny and barely functional. On each side of the upper jaw, there are two relatively simple premolars. The tongue is very long and protrusible. (Francis 1985; Lekagul 1977; Medway 1969; Nowak 1999; Parker 1989; Tate 1947)

  • Range mass
    187 to 255 g
    6.59 to 8.99 oz
  • Range length
    290 to 392 mm
    11.42 to 15.43 in

Reproduction

Rhinosciurus usually nests in hollow logs. Females have two pairs of mammae and their litters can range from one to two offspring. The offspring are born both blind and naked. (Hayssen et al. 1964; Nowak 1999)

  • Range number of offspring
    1 to 2
  • Average number of offspring
    1.3

Behavior

The long-nosed squirrel is usually solitary and quite rare. When it is active, this squirrel holds its tail up with fluffed-out hairs. Because it is hardly seen in nature and rarely trapped, not much is known about the behavior of Rhinosciurus. (Francis 1985; Lekagul 1977; Medway 1969; Nowak 1999)

Communication and Perception

Food Habits

Although R. laticaudatus is onmivorous, it is one of only a few species of squirrels that is mainly insectivorous. Rhinosciurus eats a variety of foods ranging from insects and small non-insect invertebrates to fruits. The stomach of a trapped specimen was found to contain insects and earthworms. A living specimen was observed eating almost 30 grasshoppers and 12 earthworms a day. Its diet was also supplemented with a banana and plenty of water. These squirrels are attracted by conventional baits, but rarely eat much of them.

Rhinosciurus is highly modified for its typical small-animal diet of insects and earthworms. Its long, tapered snout, reduced upper incisors, slender lower incisors and long, highly protrusible tongue are good adaptations for life as an insectivore on the forest floor. The teeth of older specimens are usually worn down significantly. This is probably due to the dirt and grit taken in when eating insects. (Lekagul 1977; Medway 1969; Nowak 1999; Parker 1989)

Foods eaten include: ants, termites, beetles, earthworms, grasshoppers and fruit.

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods
  • terrestrial worms
  • Plant Foods
  • fruit

Conservation Status

Other Comments

Because of its long snout, Rhinosciurus closely resembles the tree shrew(Tupaiidae). In fact, the resemblence is so astonishing that many local people can not distinguish between the two and thus call them both by the same name, tupai.

Rhinosciurus laticaudatus is also known by several other names including Rhinosciurus incultus, Rhinosciurus leo, Rhinosciurus peracer, Rhinosciurus rhionis, Rhinosciurus saturatus, and Rhinosciurus tupaioides.

(Grzimek 1975; Wilson and Reeder 1993)

Contributors

Jason Pietryga (author), University of Michigan-Ann Arbor, Kate Teeter (editor), University of Michigan-Ann Arbor.

Glossary

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

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.

carnivore

an animal that mainly eats meat

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.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

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

sexual

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

solitary

lives alone

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Chasen, F. 1946. Handlist of Malaysian Mammals. Singapore: Bulletin of the Raffles Museum.

Francis, C., J. Payne, K. Phillipps. 1985. A Field Guide to the Mammals of Borneo. Petaling Jaya, Malaysia: Seteakawan Printers.

Grzimek, B. 1975. Grzimek's Animal Life Encyclopedia. New York, New York: Van Nostrand Reinhold Company.

Hayssen, V., A. von Tienhoven, A. von Tienhoven. 1964. Asdell's Patterns of Mammalian Reproduction. Ithaca, New York: Constock Publishing Company.

Lekagul, B., J. McNeely. 1977. Mammals of Thailand. Bangkok, Thailand: Kurusapha Ladprao.

Lim, B., K. Lim, H. Yong. 1999. The Terrestrial Mammals of Pulau Tioman, Peninsular Malaysia, with a Catalogue of Specimens at the Raffles Museum, National University of Singapore. Raffles Bulletin of Zoology, 6: 101-123.

Medway, L. 1969. The Wild Mammals of Malaya. London, England: Oxford University Press.

Nowak, R. 1999. Walker's Mammals of the World. Baltimore, Maryland: The Johns Hopkins University Press.

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

Tate, G. 1947. Mammal of Eastern Asia. New York, New York: The Macmillan Company.

Wilson, D., D. Reeder. 1993. Mammal Species of the World. Washington: Smithsonian Institution Press.