Zoo officials say Inji is in amazing shape despite being "ultra-geriatric."

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

Inji, the Sumatran orangutan described by the zoo as “ultra-geriatric,” is believed to be 60 years old, and the oldest orangutan in the world.

“Inji’s in amazing shape for her age,” said Asaba Mukobi, the zoo’s senior primate keeper. “She has no major health concerns — she isn’t taking any special medication."

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,” Mukobi said.