Kealoha, who zoo officials say was a favorite chimpanzee of visitors for nearly two decades, passed away Friday morning. 

The cause of death is unknown. 

The cause of death is being determined, and extensive laboratory tests taken during the period when he began showing signs of illness are being reviewed. Earlier this week zookeepers were alerted that there were potential health issues when Kea became lethargic.

Kea was admitted to the Zoo’s Veterinary Clinic Tuesday for a complete examination when he did not respond to medication.  The cause of death will be determined when all lab results are completed.

Kea is survived by his parents Roscoe and Kumi, and older brother Kibale. Members of the zoo staff are making all efforts to allow his survivors to express their loss and appropriate grieving behaviors. The Honolulu Zoo’s chimpanzee community is comprised of five males and three females.