Animal Behavior: Love at the Zoo

Nothing frustrates zoo curators quite so much as trying to mate stubbornly uncooperative animals. Though many wild beasts are compliant enough about breeding behind bars, others seem to lose their reproductive urge as soon as they lose their freedom. But their sexual indifference to their own kind, Zurich Zoologist Heini Hediger told a symposium on animal behavior in San Francisco last week, may obscure a simple fact: they sometimes learn to prefer their keepers to their natural mates.

As director of the Zurich Zoo, Hediger did not have to search far for...