Celebrating Seniors - Western Lowland Gorilla

Healthy Habits

JoJo, one of the zoo’s two silverback gorillas, is now 31—a number that marks him as geriatric for his species. Thanks to expert animal care, the dominant ape doesn’t show any signs of aging. Like many of us, though, he can require a little extra motivation to keep his health on track.

“He just loves to eat,” says Curator of Primates Maureen Leahy. “That’s one thing we have to monitor.”

JoJo’s alpha status means that he often gets first dibs on the highest-calorie items in their diet. As a result, he tipped the scales at 560 pounds four years ago, when Leahy arrived at the zoo. Silverback gorillas are naturally massive mammals, but that extra bulk put him at risk for arthritis and heart problems.

To stave off those issues, animal care staff at Regenstein Center for African Apes adjusted JoJo’s diet and started him on a voluntary fitness routine. Leafy greens were prioritized over high-calorie “biscuits” in the daily diet. The biscuits that were deployed were featured in “puzzle feeders” high in the exhibit, encouraging JoJo to climb more and manipulate the feeders with his fingers to get the high-energy items in his diet.

A calisthenics routine was also added to his daily operant conditioning sessions to encourage the great ape to move more. “We use positive reinforcement to have him stand, sit, do leg lifts and move about through the exhibits,” says Leahy. “At first we had to build his endurance, but now he has a lot more stamina.” Indeed, JoJo currently weighs in at a relatively trim 475 pounds.

As the gorilla ages, animal care staff continue to proactively monitor his health. When JoJo is sedated for his scheduled physical examinations, a cardiologist does a full cardiac workout to check his heart health. Keepers are also working to add dental care to daily wellness checks—another way to head off potential problems. As they say, a little prevention is better than the best cure.


by James Seidler • Originally published September 14, 2011

  Celebrating Seniors

Join us to celebrate all the zoo’s seniors! Sundays in September will be dedicated to special chats highlighting the exceptional care provided to the zoo’s elder statesmen.

September 4, 11, 18 & 25
Learn more about the celebration!