The erudite ape was 44 and had suffered heart trouble possibly linked to his smoking habit from his younger days.
Booie lived at the Wildlife Waystation in Sylmar where he was a longtime favorite of visitors in large part because of his ability to sign. KNBC-TV, Los Angeles, said Booie was nicknamed "The Signing Chimp."
"He had fans all over the country," Wildlife Waystation founder Martine Colette told KNBC.
Booie had been a pet early in his life and also had his mettle tested as a lab animal at a New York University vaccine research facility before finding a permanent home with Colette outside Los Angeles in 1995.
Along with a roof and three squares a day, Colette also put a stop to Booie's cigarette habit