Like the great elder statesman that he is, one of the two oldest male zoo chimpanzees in North America spent time affably greeting old friends and other visitors during a rare public appearance Wednesday at Lincoln Park Zoo.
The chimp named Keo usually lives behind the scenes in a non-public area of the Regenstein Center for African Apes, ceding the spotlight to the zoo's second, younger chimp troop. But in honor of his 50th birthday June 26, the zoo this week put Keo back on public exhibit with the three females in his group.
On Wednesday, Keo quickly recognized two familiar visitors he last saw more than a year ago, when he was last on display. Rushing over to retired airline pilot Joe Schenke and his wife, Judi, he planted his lips on the window as if to offer a kiss.
"He just loves my wife," said Schenke, who said they sometimes visit the apes every day of the week. "He will sit with his back against the window and want you to scratch it from the other side of the glass. He'll even turn to look, like he's making sure you're moving your hand, even though he can't feel it."
Keo's life at Lincoln Park during the last 49 years has made the chimp a walking history of zoos and the way they've changed in mission and in attitude, said Steve Ross, the zoo's supervisor of behavioral and cognitive research.
Born in Africa, Keo was taken from the wild as a year-old infant to Lincoln Park. There, he was raised by humans. Today, importing wild chimps is illegal, and most chimps born in zoos are raised by other chimps.
Much of Keo's childhood was spent in the children's zoo, where he was called upon to wear a hat and preside over pretend tea parties, once a favorite for zoo publicity photos. In his old age, Keo was the first ape in Lincoln Park trained to use a touch-screen computer as a part of cognitive experiments Ross launched three years ago.
"He has gone from tea parties to touch-screen computers," Ross said. "In the 49 years he has been here, he has witnessed incredible changes in how zoos operate and care for their animals."