Delilah was born at Oregon Zoo on May 25, 1973, and is the daughter of Coco, who passed away in 2012. Delilah was hand-reared and was introduced to the chimp project with orphan chimps in her first year. When she was seven years old, she was integrated with the older chimps.

For a time, Delilah enjoyed being the alpha chimp, but Chloe eventually became more dominant. Delilah was thrilled to meet Jackson (the zoo's new male chimpanzee) – jumping up and down and making giggling noises when she saw him.