(Portland, OR) -- A chimpanzee at the Oregon Zoo who helped launch a decades-long friendship with renowned primatologist Jane Goodall has celebrated a landmark birthday. Delilah turned 50 and while she's one of the oldest animals at the zoo, she's not the oldest chimp. Jackson is 51 and Chloe is 54. The average age for chimps in a zoo is 41. Delilah was born at the zoo in 1973 and drew the attention of Goodall who visited regularly, getting to know Delilah and the others. She helped raise funds for the zoo's new primate area that opened in 2020.