The world's only known albino orangutan climbed trees, foraged for food and began building a nest after being released into a remote Borneo jungle more than a year after conservation officials found her starving and dehydrated in an Indonesian village.
The Borneo Orangutan Survival Foundation says the great ape, called Alba after thousands worldwide responded to an appeal for a name, has tripled in weight since being rescued in April last year. Her name means "white" in Latin and "dawn" in Spanish.
She was found with dry blood smeared around her nose -- the result of her violent capture -- and weighed just 8 kilograms, the BOSF said.
The blue-eyed primate, covered in fuzzy white hair, and another rehabilitated orangutan, Alba's best friend Kika, were released inside Bukit Baka Bukit Raya National Park on Wednesday after a more than 24-hour journey from their rehabilitation center by vehicle, boat and hiking.
"So far she's showing good signs of adapting," Nico Hermanu, a BOSF spokesman, told AFP.
"She's been climbing trees as high as 35 metres (about 115 feet) and has been eating fruit from the forest."
Kika and Alba -- who is six years old and now 28 kilos -- will be monitored by conservation teams.
The foundation originally planned to create a 5-hectare (12-acre) "forest island" for Alba rather than a release into truly natural habitat because of health issues related to her albinism including poor sight and hearing and the possibility of skin cancer.
But the government's Natural Resources Conservation Agency and other agencies decided it was appropriate to release Alba into the wild because of her strong physical condition and intrinsically wild behavior.
She will be electronically tracked and regularly monitored by a medical team.
"Alba has no inferiority complex as we imagined before. She is very confident compared to other orangutans," said veterinarian Agus Fathoni.
"I think the real threat actually comes from humans. What we're worried about is poaching where this very special condition makes her a target," he told The Associated Press.
Patrols of Alba's new home by national park and conservation agency staff will aim to deter poachers, though they admit the number of personnel is limited.
"We don't have enough to cover all the area of the national park but we're confident of covering all the patrol lines that we have set," said national park official Wirasadi Nursubhi.
Orangutans, reddish-brown primates known for their gentle temperament and intelligence, are critically endangered and only found in the wild on the Indonesian island of Sumatra and on Borneo, which is divided among Indonesia, Malaysia and Brunei.
The International Union for Conservation of Nature, which declared Borneo's orangutans critically endangered in 2016, says their numbers have dropped from about 288,500 in 1973 to about 100,000 today as destruction of forests and plantation agriculture for logging, paper, palm oil and mining destroyed and fragmented their forest habitat.
The Sumatran orangutan is a separate species and has been critically endangered since 2008.
Alba, approximately five years old, was given final medical tests and anesthetized for the journey to Bukit Baka Bukit Raya.
Workers shouted "Alba's going home" as her cage was lifted onto a truck at the Nyaru Menteng Rehabilitation Center in Central Kalimantan province on Borneo.
"It's true this is a big gamble but we hope that with our collaboration we will win the big bet we have made today" said the orangutan foundation's chief executive Jamartin Sihite after releasing Alba from her cage.
A string of fatal attacks on the great apes this year have been blamed on farmers and hunters.
Four Indonesian men were arrested over the killing of an orangutan shot some 130 times with an air rifle in February.
Borneo police have also arrested two rubber plantation workers and accused them of shooting an orangutan multiple times before decapitating it.
Plantation workers and villagers are sometimes known to attack the animal because they see it as a pest, while poachers also capture them to sell as pets.