Java Mouse-Deer

Java Mouse-Deer

Javan chevrotain, Javan mousdeer, Java Mousedeer

Kingdom
Phylum
Subphylum
Class
Order
Family
Genus
SPECIES
Tragulus javanicus
Population size
Unknown
Life Span
14 yrs
WEIGHT
1-2 kg
HEIGHT
30 cm
LENGTH
45 cm

The Java mouse-deer is the smallest living ungulate; when it reaches maturity it is about the size of a rabbit. These tiny animals have a triangular-shaped head, arched back, and round body with elevated rear quarters. Their thin, short legs are about the diameter of an average pencil. Although Java mouse-deer do not possess antlers or horns, males have elongated, tusk-like upper canines that protrude downward from the upper jaw along the sides of their mouth. Males use these “tusks” to defend themselves and their mates against rivals. Females can be distinguished from males because they lack these prominent canines, and they are slightly smaller than the males. Java mouse-deer can furthermore be distinguished by their lack of upper incisors. The coloration of their coat is reddish-brown with a white underside and there are pale white spots or vertical markings on their necks.

Distribution

Java mouse-deer are native to Java, Indonesia, and perhaps Bali, although sightings there have not been verified. They live in tropical moist forests and it has been argued that they favor areas of dense vegetation along riverbanks.

Geography

Continents
Subcontinents
Countries

Climate zones

Habits and Lifestyle

Java mouse-deer are crepuscular, meaning they prefer to be active during the dim light of dawn and dusk. During the day, they roam in crown-gap areas with a dense undergrowth of creeping bamboo, through which they make tunnels through the thick vegetation which lead to resting places and feeding areas. At night, they typically move to higher and drier ridge areas. Although Java mouse-deer form family groups, they are usually shy, solitary animals. They are also usually silent and the only noise they make is a shrill cry when they are frightened. Males are territorial, marking their territory and their mates with secretions from a scent gland under their chin. This territorial marking usually includes urinating or defecating to mark their area. To protect themselves and their mates or to defend their territory, mouse-deer slash rivals with their sharp, protruding canine “tusks.” When threatened, Java mouse-deer will also beat their hooves quickly against the ground, reaching speeds of up to 7 beats per second, creating a “drum roll” sound. The territories of males and females overlap considerably, yet individuals of the same sex do not share their territories. When giving birth, however, females usually establish a new home range. Additionally, males may travel distances of 519 meters (1,703 ft) daily on average, while females average 574 meters (1,883 ft) daily.

Group name
Seasonal behavior

Diet and Nutrition

Java mouse-deer are primarily herbivores (folivores) and their diet consists of anything they find on the ground in the dense vegetation. They eat leaves, shrubs, shoots, buds, and fungi, in addition to fruits that have fallen from trees.

Mating Habits

MATING BEHAVIOR
REPRODUCTION SEASON
November-December in the wild; year-round in captivity
PREGNANCY DURATION
4.5 months
BABY CARRYING
1 fawn
INDEPENDENT AGE
12 weeks
FEMALE NAME
doe, hind, cow
MALE NAME
buck, stag, bull
BABY NAME
fawn, ass

Java mouse-deer are monogamous and form pairs. According to some sources, in the wild, they breed from November to December. In captivity, they may breed yer-round. The gestation period usually lasts 4.5 months or 144 days. Typical litters consist of a single fawn, which resembles a miniature adult, although the tusk-like incisors prevalent in males are not visible in the young mouse-deer. The average mass of a newborn fawn is 370 grams (13 oz), and it is capable of standing within 30 minutes after birth. The fawn will start eating solid food within 2 weeks but will be completely weaned at around 12 weeks old. On average, it takes the young, both male and female, 167 days ( around 5 months) to reach reproductive maturity.

Population

Population threats

The main threat to the Java mouse-deer comes from humans. Through the destruction of their habitat, as well as from hunting and trapping the mouse-deer for food, their pelts, and for pets, humans have considerably reduced the Java mouse-deer population. These animals are particularly vulnerable to being hunted by humans at night because of their tendency to freeze when illuminated by having a spotlight shone on them. Because of the small size of the Java mouse-deer, dogs are also a common predator for them, as well as crocodiles, big cats, birds of prey, and snakes.

Population number

The IUCN Red List and other sources don’t provide the number of the Java mouse-deer total population size. Currently, this species is classified as Data Deficient (DD) on the IUCN Red List.

References

1. Java Mouse-Deer on Wikipedia - https://en.wikipedia.org/wiki/Java_mouse-deer
2. Java Mouse-Deer on The IUCN Red List site - https://www.iucnredlist.org/species/41780/61978138

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