The shocking discovery of a blind orangutan riddled with air rifle pellets and on the verge of death has highlighted the ongoing plight of the endangered species.
Tengku, an adult male orangutan, is fighting for his life in the intensive care unit of a veterinary hospital after being rescued by workers from the Orangutan Information Centre (OIC) in Sumatra, Indonesia last Saturday. He is one of many orang-utans to have been injured, trafficked or killed by poachers in the region.
Workers from the OIC - a non profit organisation - and Gunung Leuser National Park found Tengku with a "prolapsed anus ... most likely a result of being shot in that area by an air rifle" in the area of Batu Katak.
"The orang-utan was roaming in plantation in Batu Katak village for weeks until our team discovered the orang-utan needing help," a statement from the OIC read.
"As soon as we sedated the orang-utan safely, our team sent the orang-utan to Sumatran Orangutan Conservation Programme (SOCP) quarantine for further medical check and treatment."
It wasn't until a veterinary team took X-rays of Tengku for emergency surgery that they realised the severity of his injuries. The X-rays revealed Tengku had "66 pellets from an air rifle throughout his body".
"Multiple pellets entered in and around Tengku's eyes, one of which is completely blind and will need to be removed in the near future," a statement from SOCP read.
Tengku today remained in intensive care at the SOCP quarantine. His prognosis is unknown. But his case is not rare.
Tengku is the fourth wild adult orang-utan with "serious injuries caused by air rifles" SOCP has received in just three months.
"This is the second case of an adult male wild orang-utan arriving to our quarantine centre with a prolapsed anus due to pellets within the last two months," a SOCP spokesman said.
"Another (was a) severely injured adult male orang-utan rescued from plantation in Langkat, North Sumatra."
The OIC says it has saved at least 24 orang-utans so far this year.
"(We) are sadly receiving reports of animals needing help all the time," a statement from the Centre read.
OIC founder and director Panut Hadisiswoyo told news.com.au that orang-utans were poached for several reasons.
"Some farmers who suffer economic loss (shoot them) as orang-utan raid their crops, some other people who become opportunistic poachers also shoot orang-utans as they have easy access to them," he said.
The forest dwelling primates are typically poached in areas where their habitat has been destroyed by palm oil plantations and they are most vulnerable.
Mr Hadisiswoyo said at least 10 orang-utans were trafficked last year just in Sumatra with many more cases thought to be unidentified.
"(They are trafficked) mainly for pets and some trafficked to illegal zoos and safaris," Mr Hadisiswoyo said.
"(There is a black market for orang-utans because) some people have misperception about loving orang-utan by keeping orang-utans as pets."
But the animals belong in the wild, he said. Life for orang-utans in illegal captivity is not much of a life at all.
"Orang-utans when they are young are so cute and easy to be trained to act like human," Mr Hadisiswoyo said.
"When orang-utan is still very young, (illegal owners) put orang-utan in their homes, then when grow bigger they chained orang-utans and then put in a cage."
According to the Orangutan Project, orang-utans are "extremely patient and intelligent mammals". "They are very observant and inquisitive, and there are many stories of orang-utans escaping from zoos after having watched their keepers unlock and lock doors," the Orangutan Project's website states.
Both the Sumatran and Bornean species of orang-utan are classified as Critically Endangered according to the International Union for the Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species.
Humans have reportedly killed more than a million orang-utans, yet not one has killed a human, despite being seven times physically stronger. But it's not just hunters with air rifles that threaten to wipe out orang-utans.
Eighty per cent of their natural habitat has been destroyed by logging, palm oil plantations and forest fires. Some experts predict orang-utans will be extinct in South East Asia within 10 years. The OIC estimates there are about 14,500 orang-utans left in Sumatra and 45,000 in Borneo.
Mr Hadisiswoyo said the organisation had several strategies in place to reduce the poaching of orang-utans but that more needed to be done to save them from extinction.
"We have an anti poaching patrol team and we also have a Human Orangutan Conflict Response Unit (HOCRU) that monitors conflicts and educates local people by training local farmers to mitigate the conflict in safe and responsible ways," he said.
"Law enforcement (is the only thing that can stop illegal poaching) as so far there is no effective deterrent in place ... only traders have been prosecuted but people who keep and shoot orang-utans are not prosecuted."
One petition on change.org - which has garnered thousands of signatures - has called on the Indonesian government to better enforce laws that state air rifle owners are only authorised to use the weapons for sports purposes. They want air rifle owners who shoot orang-utans to have their licenses revoked.
"Such acts would help protect and save the wildlife from the unnecessary death," the petition reads.