By Eduardo Reyes
Geographic Range
Javan rusa are found on most of the islands of Southeast Asia. They occur from Malaysia in the west to New Zealand in the east. ()
Biogeographic Regions:
oriental 
(native ); australian (native ).
Habitat
Javan rusa are principly found in deciduous forests, plantations and grasslands in the islands of Southeast Asia. They prefer the edges of the forest. ()
These animals are found in the following types of habitat:
tropical ; terrestrial .
Terrestrial Biomes:
forest ; scrub forest .
Physical Description
(162.8 to 352 lbs; avg. 257.4 lbs)
(32.68 to 43.31 in; avg. 37.99 in)
Male Javan rusa are larger than females. Males usually weigh 152 kg, while females weigh about 74 kg. The males have a lyre-shaped, three-tined antlers, which weigh about 2.5 kg. Males and females have a rough grayish brown coat that is often coarse in appearance. Their ears are rounded and broad. The animals look short and stubby because they have relatively short legs. ()
Some key physical features:
endothermic ; bilateral symmetry .
Sexual dimorphism: male larger, ornamentation .
Reproduction
Javan rusa breed once yearly.
Breeding peaks from July to September.
Like other deer species, Javan rusa have a polygynous mating system, with males competing for access to receptive females.
Mating systems:
polygynous .
The gestation period is 8 months. They give birth to 1 calf, rarely 2. Breeding occurs throughout the year but peaks during the months between of July and September.
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
Newly born calves stay with their mother. Weaning is from 6 to 8 months. These deer reach sexual maturity 18 to 24 months after birth. ()
Parental investment:
precocial ; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female).
Lifespan/Longevity
Javan rusa live between 15 to 20 years in the wild and in captivity. Rarely do they live for more than 20 years. ()
Behavior
Javan rusa are primarily nocturnal but they can browse and graze during the day. During the mating season, males decorate their antlers with grass and twigs to attract the females and intimidate competitors. Males are extremely vocal and aggressive towards one another. Males and females live separately most of the year, except during the mating season. Young calves stay with their mothers until they reach sexual maturity. They are gregarious, normally associating in herds. ()
Home Range
Home range sizes of Javan rusa are not known.
Key behaviors:
cursorial; terricolous; nocturnal ; crepuscular ; motile ; nomadic ; social .
Communication and Perception
Javan rusa, like other deer species, use chemical and visual cues and sounds in communication around reproductive state.
Food Habits
Like most deer, Javan rusa eat primarily grass and leaves. They hardly drink any water because they get their fluid from the grass and the leaves. ()
Plant Foods:
leaves; wood, bark, or stems.
Predation
- crocodiles (Crocodylus)
- pythons (Boidae)
- Komodo dragons (Varanus komodoensis)
Although the Javan deer sometimes graze during the day, they are mostly nocturnal to avoid diurnal predators. Their primary predators are crocodiles, pythons, and Komodo dragons. ()
Ecosystem Roles
Javan rusa help disperse seeds in the forest.
Key ways these animals impact their ecosystem:
disperses seeds.
Economic Importance for Humans: Negative
Javan rusa have a direct impact on farming through competition with domestic stocks. The competition for pasture, between the deer and domestic animals use for farming, seems to be a very important issue in Indonesia. Also, Javan rusa eat crops and sometimes spread weeds that are harmful to farming. ()
Ways that these animals might be a problem for humans:
crop pest.
Economic Importance for Humans: Positive
Javan rusas shed their antlers between the months of October and February. These are collected and used primarily in Asian medicine. Also, the antlers can be used as jewelry. In Queensland, Australia, 50% of the deer farmed are Javan rusa. While economic by-products such as hides offer some income to rusa farmers in Australia, the major commercial activity from rusa deer farming is deer meat (venison) production. Venison is considered a lean and nutritious red meat. ()
Ways that people benefit from these animals:
food ; body parts are source of valuable material; source of medicine or drug .
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Migratory Bird Act: [link]:
No special status.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
Javan rusa are not considered endangered currently.
Other Comments
Javan rusa are the largest Rusa species. They were previously known by the scientific name Cervus timorensis.
Contributors
Eduardo Reyes (author), University of Michigan.
Bret Weinstein (editor), University of Michigan.
