The adult female was found on Wednesday in a critical condition inside a palm oil plantation in the Central Kalimantan province, the Borneo Orangutan Survival Foundation said in a press release.
The case is the latest example of one of the critically- endangered primates being killed by humans. Orangutans are faced with extinction from poaching and the rapid destruction of their forest habitat, driven largely by land clearance for palm oil and paper plantations.
The primate's right upper leg was also broken and maggots were found inside her open wounds. She also very skinny due to malnutrition.
A team of medics operated on the orangutan in an attempt to save her life but she died yesterday, the foundation said.
The group estimates that the attack took place three days before she was found.
"This added a long list of conflict between between industry and wildlife, as well as (the) practice of nature exploitation," it said, urging Indonesian government to take a real action to protect the primates.
Orangutans are native to the vast island of Borneo, which is shared among Indonesia, Malaysia and Brunei.
Destruction of Indonesia's lowland rainforest and peatland for palm oil plantations and agriculture has led to a dramatic decline in the number of orangutans, Asia's only great ape.
