Call it a natural disaster. The San Diego Zoo spent $3.5 million to build a designer forest that would house five adolescent Malayan sun bears. The zookeepers planted some trees, dug a moat, launched a waterfall, even hooked up a fiber-glass tree with an electric honey dispenser. As company for their wards, they invited lion-tailed macaques, yellow-breasted laughing thrushes, orange-bellied fruit doves and Indian pigmy geese.
When the lush exhibit opened this summer, zoogoers loved it. So did the bears. They shredded the trees, rolled up the sod, plugged the moat -- and then one attempted a fast break over the...