PORTLAND, Ore. — The Oregon Zoo on Wednesday celebrated the birthday of its oldest resident.

Inji, the Sumatran orangutan described by the zoo as “ultra-geriatric,” is believed to be 59 years old, and the oldest orangutan in the world.

Inji’s actual birth date isn’t known. Zoo officials said Inji was born in the wild and came to the United States through the wild animal trade, which was legal at the time. She was brought to the zoo by her owner in 1961. She was estimated to be about a year old when she arrived at the zoo on Jan. 30, 1961.

“We’re thankful that we’ve been able to give Inji a good home, but it’s heartbreaking to think about the circumstances that brought her here,” said Asaba Mukobi, the zoo’s senior primate keeper. 

Despite her age, Mukobi says Inji is still going strong.

“Inji’s in amazing shape for her age,” Mukobi said. “She has no major health concerns — she isn’t taking any special medication beyond aspirin.”

Inji currently can’t been seen by zoogoers as work on the new Primate Forest area is being completed.