Puan, 62, was euthanised on Monday after suffering age-related complications that the Australian zoo said were affecting her quality of life.
Believed to have been born in a jungle in Sumatra, Indonesia, in 1956, she had been at the zoo since 1968, and was officially recognised by Guinness World Records as the oldest of her species in 2016.
Zookeeper Martina Hart, who had worked with Puan for 18 years, wrote a heartfelt obituary after her death, which was printed in full in the West Australian newspaper.
She said: “Over the years Puan’s eyelashes had greyed, her movement had slowed down and her mind had started to wander. But she remained the matriarch, the quiet, dignified lady she had always been.
“Puan demanded and deserved respect, and she certainly had it from all her keepers over the years ... Puan taught me patience, she taught me that natural and wild instincts never disappear in captivity.
“She was in a zoo environment, but to the end she always maintained her independence. I feel so grateful to have been in her life, albeit to have been such a small part of her life.”
Puan has been a key member in orangutan breeding programs for most of her life. She gave birth to 11 children, and has 54 descendants in Australia, the US, Indonesia and elsewhere around the world.
“Apart from being the oldest member of our colony, she was also the founding member of our world-renowned breeding program and leaves an incredible legacy,” said Holly Thompson, the zoo’s primate supervisor in a statement.
“Her genetics count for just under 10% of the global zoological population.”
Sumatran orangutans are a critically endangered species and rarely reach age 50 in the wild. According to the World Wildlife Fund, there are only about 14,600 of the orangutan worldwide.