Satu, a male orangutan at the San Diego Zoo, died on Wednesday. He was 26.
The zoo announced Satu's death on social media on Thursday, saying the orangutan's cause of death is likely to be related to cancer.
Satu had been under veterinary care for serious illness, the zoo said, but collapsed and was unable to be resuscitated.
The zoo called Satu a “much-loved ape” and “charismatic primate.” Other details were not immediately available.
Satu was born at the zoo in 1995. He sired two offspring, a male named Cinta and a female named Aisha.
“Satu was known to be patient, curious, engaging and sensitive. He will be greatly missed by the wildlife care specialists, medical team, volunteers, and guests alike,” the zoo said in a statement.
The zoo now has three orangutans, Aisha, Karen and Indah after Satu's death, The San Diego Union-Tribune reported.
Bruno, a male orangutan at the Los Angeles Zoo, died earlier this month at 42. Native to the jungles of Indonesia and Malaysia, there are three species of orangutans, all of which are critically endangered.