The oldest chimpanzee living at the San Francisco Zoo & Gardens has died Saturday at the age of 63, zoo officials announced. 

The chimpanzee, who was named Cobby, had been a performing chimpanzee before he was brought to the zoo in the 1960s. Zoo officials believe the chimpanzee’s old age was a factor in its death, but they have yet to determine the cause. 

“Cobby was part of San Francisco,” Tanya M. Peterson, executive director of the San Francisco Zoological Society, said in a statement. “He touched so many lives, and people have so many memories of him. He is irreplaceable, and our hearts are broken. We will all miss seeing his handsome grey beard watching over us from the top platform of the yard.”

Chimpanzees, considered to be endangered creatures, have an average life expectancy of 33 years in the wild and 60 years under human care.