Primatologist Elizabeth Lonsdorf discusses chimpanzee 'fishing' behavior at Lincoln Park Zoo in Chicago

Alan visits a troupe of seven chimpanzees at the Lincoln Park Zoo in Chicago and learns from them how to go fishing in an artificial termite mound — not for termites, but for ketchup. Just how the chimps themselves learn to deftly insert sticks into the mound is what fascinates primatologist Elizabeth Lonsdorf, who first watched chimps termite fishing in Africa.

Alan sees for himself what Elizabeth discovered in her studies of wild chimps: that there are big differences between how boy and girl chimps learn. The young females in the Lincoln Park Zoo quickly picked up the skills of fashioning appropriate tools and fishing out the ketchup from holes in the mound. One young female, Chuckie, is so good at making fishing sticks that they are regularly stolen from her by the other chimps. By contrast, the troupe's alpha male appears bored by the whole idea, while the youngest male, Kipper, prefers to swipe his mother's ketchup off her stick with his hand.

The chimps' ketchup fishing is a big hit with the public at the zoo, and Elizabeth hopes that the intriguing parallels and differences between how humans and chimps learn will motivate zoo visitors to support one of her main goals: furthering the conservation of endangered chimpanzee populations in the wild.