Diets high in fat and simple sugars aren't harmful only to humans. Heart disease is the number one killer of male Western lowland gorillas.
Like humans, gorillas are being afflicted with life-threatening diseases due to the diet they are consuming in zoos. To reverse the effects of the unhealthy diets the gorillas ate, researchers at Cleveland Metroparks Zoo did away with the high-sugar and high-starch foods they had been feeding them and, instead, provided them with diets similar to those they'd eat in the wild.
Mokolo and Bebac, two gorillas found in Cleveland's Zoo, now eat a combination of healthy greens, tree branches, flax seeds and vitamins. In comparison to the few hours they used to spend eating their meal, the gorillas now feed over the course of the day, spending up to 50-60% of their day foraging. This is similar to the amount of time wild gorillas spend feeding.
Although they take in twice as many calories on the new diet, after a year, the big boys of the primate house have dropped nearly 65 pounds each and weigh in the range of their wild relatives.Kristen Lukas, an adjunct assistant professor of biology at Case Western Reserve and chair of the Gorilla Species Survival Plan (SSP) for the Association of Zoos and Aquarium (as well as the curator of Conservation and Science at the Cleveland Zoo) says, "We're just recognizing that surviving on a diet and being healthy on a diet are different."
Elena Hoellein Less, a PhD candidate in biology at Case Western Reserve University, has been monitoring how the change in diet has affected the gorillas' habits. She's also been busy studying the correlation between heart disease and a plants-based diet, and is concerned with bringing the level of muscle in the zoo gorillas up to same levels in their wild cousins.
Other Gorilla SSP institutions are testing the new diet in zoos all over North America, and results are expected later this year. If the results prove beneficial to the gorillas' overall health, the Gorilla SSP may endorse high-fiber foraging at zoos nationally and internationally.
Photo credit: cc: flickr.com/photos/leamaimone