[5] The Javan rusa natively occurs on the islands of Java, Bali and Timor in Indonesia.

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.

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.

[citation needed] As with other deer species, Javan rusa mainly feed on grass, leaves, and fallen fruit.

[5][10] The Javan rusa mates around July and August, when stags contest by calling in a loud, shrill bark and dueling with the antlers.

Calves are weaned at 6–8 months, and sexual maturity is attained at 3–5 years, depending on habitat conditions.