Heart disease doesn’t just hit humans. It’s the leading killer among male zoo gorillas, and scientists want to know why. Obesity? Perhaps, but the term has yet to be defined for the primates. Diet? Likely, and Elena Hoellein Less of Cleveland Metroparks Zoo is trying to prove it. As part of a multi-zoo study, she’s been feeding her two gorillas, Bebac and Mokolo, a trial menu meant to mimic the largely vegetarian one eaten in the wild. Heavy on leafy greens, the new diet is also modeled after a heart-healthy human one, says Less. Judging by the 65 pounds each of her charges has shed so far, it’s nothing to take lightly. —Catherine Zuckerman
OLD MENU Since 2008, 22 gorillas at five zoos—in Cleveland and Columbus, Ohio; Asheboro, North Carolina; Seattle; and Toronto—have been weaned off specially formulated biscuits (left). The edibles delivered all the right nutrients but also a starchy, caloric punch.
NEW MENU The gorillas now munch on many pounds a day of slimming, fiber-rich produce—including endive, dandelion greens, romaine lettuce, and alfalfa hay.