Inji, believed to be the world's oldest orangutan and the Oregon Zoo's most senior animal, has died. She was 61 years old.

The Sumatran orangutan had been showing signs of decline over the last few years, the zoo said in a press release, but her health deteriorated rapidly in recent weeks. After she stopped eating food and responding to her medication, the decision was made to euthanize her.

"We knew she couldn't live forever, but this really hurts, and I know many visitors are grieving along with us," zookeeper Bob Lee said in a satement. "Inji's ability to connect with people was incredible. She inspired generations."

Inji was brought to America through the then-legal wild animal trade and  arrived at the zoo in 1961, when she was thought to be around a year old. Orangutans in the wild typically only live to the age of 40.

The zoo said there are plans to honor Inji when its new primate enclosure opens in the spring.