The Javan rusa or Sunda sambar (Rusa timorensis) is a large deer species native to Indonesia and Timor-Leste. Introduced populations exist in a wide variety of locations in the Southern Hemisphere. Rusa is the Malay word for "deer" in general as well as lending to name of its own genus.
Taxonomy
thumb|The Javan rusa is featured on a 1988 [[Indonesian rupiah banknote]]
Seven subspecies of the Javan rusa are recognised: Fawns are born without spots. Males are bigger than females; head-to-body length varies from , with a tail. Males weigh , female about .
Distribution and habitat
thumb|Herd of rusa deer in [[Baluran National Park]]
The Javan rusa natively occurs on the islands of Java, Bali and Timor in Indonesia. It has been introduced to Irian Jaya, Borneo, the Lesser Sunda Islands, Maluku, Sulawesi, Pohnpei, Mauritius, Réunion, Fiji, Tonga, Samoa, Vanuatu, the Solomon Islands, the Christmas Island, the Cocos Islands, Nauru, Groote Eylandt, Mainland Australia, New Caledonia, New Zealand, Papua New Guinea, New Britain, and New Ireland. The Javan rusa was introduced by the Dutch to New Guinea in the early 1900s.
Since its introduction to the West Papuan lowlands, the species has become widely dispersed and is common in much of its new range. However its population in its native range has declined markedly by approximately 10,000 individuals in the past two decades and likely faces further decline. As a result it has been listed as vulnerable in its native range and was declared as a protected species under Indonesian law in 2018.
During the 1980s and 1990s, protected areas such as national parks were used to control poaching and the effects of land conversion that destroyed grazing areas. However large numbers of Javan rusa died in Baluran National Park in Indonesia due to the loss of grazing area as a result of the invasive thorny acacia.
Ecology
Javan rusa are nocturnal, although they do graze during the day.
Reproduction
The Javan rusa mates around July and August, when stags contest by calling in a loud, shrill bark and dueling with the antlers. The doe gives birth to one or two calves after a gestation period of 8 months, at the start of spring. Calves are weaned at 6–8 months, and sexual maturity is attained at 3–5 years, depending on habitat conditions. Javan rusas live 15–20 years both in the wild and in captivity.