SAN FRANCISCO—The oldest male chimpanzee in any accredited zoo in North America, Cobby, passed away at San Francisco Zoo and Gardens on Saturday, June 5 at the age of 63. The cause of death has not been determined, but recent illness and old age may be contributing factors.

Cobby was a performing chimpanzee who treasured relationships with his caregivers and troop members, according to the San Francisco Zoo. His absence will be hard for two 52-year-old female chimps who were Cobby’s companions for over 42 years.

“Our hearts are broken with this devastating loss,” said Tanya M. Peterson, CEO and Executive Director of San Francisco Zoological Society in a news release. “He also was a favorite of visitors and staff, recognizing so many of us. He was one of the first animals whom I personally knew as Director. His death will be felt deeply by our staff, many of whom cared for him for decades.”

According to the San Francisco Zoo, Cobby enjoyed resting, eating his favorite snacks, and climbing high in the trees with his favorite female, Minnie. The male chimp leaves behind no offspring, but went by the affectionate nickname, “Papa.”

“Cobby was part of San Francisco,” said Peterson. “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.”

The average age for male chimps in captivity is 32.5 years and 40.5 for females, according to Project Chimps, a U.S. sanctuary for chimps. The average lifespan for chimps living in the wild is about 33 years except for one female chimp who was about 63 years old when she passed.