“Cobby was a part of San Francisco,” San Francisco Zoological Society Executive Director Tanya M. Peterson said in a statement to the AP.

The reason behind death is unknown, however, zoo officials stated Cobby was sick and think old age was a factor. Chimpanzees are predicted to reside 33 years in the wild and between 50 to 60 years under human care, the president advised the AP.

Cobby arrived in the San Francisco Zoo in the 1960s after being a performer and cared for a person till he was fully grown. He enjoyed snacking on his favorite foods, interacting with his keepers and has been the protective company to chimpanzee’s Minnie and Maggie, the San Francisco Zoo stated in a Facebook article.

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“He touched so many lives, and people have a lot of memories of him. He’s irreplaceable, and our hearts have been broken. We will all miss seeing his handsome gray beard watching over us in the top platform of the lawn,” Peterson stated.

All chimpanzees were placed on the endangered species list in 2015 due to habitat loss, poaching and disorder. Wild inhabitants were added into the list in 1990.