Zoo workers said Smoke, who was 43, acted as a father figure to many of the young chimps at the zoo, the St. Louis Post-Dispatch reported Wednesday.
Smoke arrived at the St. Louis Zoo in 1994 with his mate, Molly, and over the years the two acted as foster parents to many of the younger chimps, zoo officials said.
"He had a full and rewarding social life," primate curator Ingrid Porton said. "He was a kind and sometimes very goofy father to his biological and foster kids. It was not unusual to see Smoke do a headstand to clearly communicate his play intentions to shy youngsters."
After Molly died in 2004, keepers said, Smoke found a new love in Rose, who arrived in 2006.
"We will always remember the day Smoke first laid his eyes on Rose," Porton said. "It was so obvious to all of us that he was totally taken with her and always wanted to be next to her. If she moved, he moved; if he couldn't be right by her side, he would just stare at her longingly. And Rose liked him, too."