The WWF says that the 40 to 60 Javan rhinos remaining in Indonesia are the last known living members of the species, with none in captivity.
A WWF report said Tuesday that ineffective management and patrols in Vietnam's Cat Tien National Park hastened the species' decline.
But park director Tran Van Thanh says while some rangers haven't fulfilled their duties, some of the 100,000 farmers living in the area hunt exotic animals as a way to earn money.
Global demand for rhinoceros horn is driven by Asian countries where people think it cures cancer and other ailments.
