Woodland Park Zoo Blog

Posted by Elizabeth Bacher, Communications Leo, with Yola and Nadiri in the background, 2016 photo by Jeremy Dwyer-Lindgren, Woodland Park Zoo. Update on Leo’s passing We’d like to share preliminary necropsy (animal autopsy) findings with you regarding our 40-year-old male gorilla, Leo, who passed away on the evening of March 29 after a brief illness. The most significant post-mortem findings indicate the upper middle-age gorilla died from an aortic aneurysm—the internal rupture of the wall of the ascending aorta, the major artery exiting the heart. “The aortic dissection was extensive, extending into the descending aorta, down as far as the lower back region of Leo,” says Dr. Darin Collins, Woodland Park Zoo’s director of animal health. Heart disease emerged as a disease of concern and a major cause of death among all four great apes (gorillas, orangutans, chimpanzees and bonobos) in the early 1990s. In 1991, Woodland Park Zoo lost a male gorilla in his ‘20s due t...

Posted by: Gigi Allianic Leo, a 40-year-old male gorilla, passed away suddenly on March 29, 2018 after a brief illness. Photo by Dennis Dow/Woodland Park Zoo. Leonel, a male gorilla fondly called Leo, passed away last night at age 40 after a brief illness. The upper middle-age gorilla had been under a 24-hour care this week. He died in his off-view sleeping den. On Monday, the 360-pound gorilla had no interest in food or drink, and did not want to leave his den to go outdoors. The zoo’s animal health team did a visual assessment and a 24-hour treatment plan that included medications, hydration, hand feeding and observation. Plans to anesthetize him yesterday for a diagnostic exam were canceled because Leo had shown significant signs of improvement. “Leo drank and ate a lot and urinated, a positive sign of hydration. Also, his activity levels increased and we even observed play behavior, so we believed he was on the mend,” said Nancy Hawkes, PhD, Woodland Park Zoo’s director of...

Posted by Stephanie Payne-Jacobs, gorilla keeper EDITOR'S NOTE: Adult male gorillas are known as silverbacks because of the striking silver hair that grows across their back all the way down to their hips. This is not only a mark of maturity (silver hairs appear around 12 years-old), but a sign that one might be strong and determined enough to protect his troop. In most gorilla troops, the silverback is the center of attention. He is responsible for guarding the troop against outsiders, finding choice feeding sites and playing mediator between the other gorillas in the group. While silver hairs, larger canines and handsome red crowns (in Western lowland gorillas) are all visual characteristics of a mighty silverback, it is the personality and behavior of these males that determine if they will lead. This is the story of how one such silverback, Leonel, has come into his own as a protector, leader and peacekeeper — in part with a little help from a tiny, adorable baby called Yo...