Tragulus javanicuslesser mouse-deer

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Geographic Range

Tropical forest region in Southeast Asia

Habitat

Tragulus javanicus are found in overgrown primary and secondary forests in southeast Asia. They often reside around rocks, hollow trees, and dense vegetation near water. (Nowak and Paradiso, 1983)

Physical Description

Tragulus javanicus, or lesser Malay mouse deer, do not have antlers or horns. Instead, adult males have elongated, tusk-like upper canines (Nowak and Paradiso, 1983). These canines protrude from the side of the mouth. Females lack these canines. Females are also smaller than the males (Nowak and Paradiso, 1983). The cheekteeth of lesser mouse deer have a crescent pattern formed by the enamel ridges. Mouse deer have no upper incisors. The pelage of mouse deer is brown with an orange tint. The underside is white. There is also a series of white vertical markings on the neck (Grzimck, 1994). Malay mouse deer have a triangular head and a round body with elevated rear quarters. The thin legs are about the diameter of a pencil (Nowak and Parasido, 1983). T. javanicus is the smallest artiodactyl, 18-22 inches long with a tail length of 2 inches (Grzimck, 1994). The young look like miniature adults when born; however, the tusk-like incisors in the infant males are not well developed.

  • Sexual Dimorphism
  • male larger
  • Range mass
    1 to 2 kg
    2.20 to 4.41 lb
  • Average basal metabolic rate
    4.883 W
    AnAge

Reproduction

Mouse deer can breed at any time of the year. The gestation period is usually 4 1/2 months. Breeding females produce one fawn (Jinaka, 1995). The young are precocial when born and can stand within 30 minutes of birth (Grzimck, 1994). Mouse deer are shy and their fawns tend to be "hiders". The fawn is weaned for 10-13 weeks. It reaches sexual maturity at about 5-6 months. Lesser Malay mouse deer can live for 12 years.

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    144 days
    AnAge
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    167 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    167 days
    AnAge

Lifespan/Longevity

Behavior

Lesser Malay mouse deer tend to form monogamous family groups. Some are solitary. Mouse deer are very shy and try to remain unseen. They are usually silent; the only noise mouse deer make is a shrill cry when frightened (Jinaka, 1995). T. javanicus are most active during the night. Lesser Malay mouse deer travel thorugh tunnel-like trails of thick bursh to reach their feeding and resting sites, which are often in the cracks of rocks, hollow trees, and dense vegetation (Grzimck, 1994). The male mouse deer are territorial. Mouse deer regularly mark their territories, and their mates, using secretions from an intermandibular gland under the chin, an action that is usually accompanied by urinating or defecating (Nowak and Paradiso, 1983). Male mouse deer protect themselves, and their mates, against rivals by chasing or slashing them with their sharp canines. When threatened, lesser Malay mouse deer rapidly beat their hooves on the ground at speeds of up to 7 times per second, creating a 'drum roll' (Grzimck, 1994). Predators of the mouse deer include large birds and large reptiles (Nowak and Paradiso, 1983).

Communication and Perception

Food Habits

T. javanicus is a ruminant and has a three-chambered stomach (Lawlor, 1979). As ruminants, mouse deer use microorganisms that produce enzymes within the stomach to digest their food. In the wild, lesser Malayan mouse deer are commonly herbivores and folivores, eating leaves, buds, shrubs, and fruits that have fallen from trees. In zoos, mouse deer tend to eat insects as well as leaves and fruits (Nowak and Paradiso, 1983).

Economic Importance for Humans: Positive

Mouse deer are hunted for their skins. The pelage of mouse deer is smooth and the skin is used to make handbags and coats (Jinaka, 1995).

Conservation Status

The mouse deer population is threatened by hunting and habitat destruction.

One method to prevent the extinction of mouse deer is captive breeding. This is done primarily in zoos (Jinaka, 1995). (Jinaka, 1995)

Other Comments

Female lesser Malay mouse deer have the potential to be pregnant throughout their adult life, being able to conceive only 85-155 minutes after giving birth (Grzimck, 1994).

Contributors

Nicole Strawder (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

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

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.

References

Grzimck, T. 1994. Encyclopedia of Mammals. New York: McGraw-Hill Publishing Company.

Jinaka, H. 1995. Endangered Animal of February 1999 -Mouse Deer. A Guide to the Threatened Animals of Singapore, 2: 38-39.

Lawlor, T. 1979. Handbook to the Orders and Families of Living Mammals. Eureka: Mad Rivers Press.

Nowak, R., J. Paradiso. 1983. Walker's Mammals of the World. Chicago: John Hopkins University Press.