FILE- An elephant munches on hay while moving about inside her enclosure at the Chaffee Zoo in Fresno, California. (Craig Kohlruss/Fresno Bee/Tribune News Service via Getty Images) FRESNO, Calif. - Mabu saunters across a grassy field and raises his long, gray trunk to wrangle food from a hole carved inside a large boulder, captivating the attention of a girl propped up on her father's shoulders.At this zoo in a central California farming community, the 32-year-old African elephant is key not only to drawing visitors but also to ensuring there are elephants for zoogoers to see in the years to come — a future some animal lovers want to avoid.Over the past year, the Fresno Chaffee Zoo has been pulled into a growing global debate over the future of elephants in zoos.