Brookfield, Ill. — The Chicago Zoological Society is saddened to announce Nakili (pronounced Nah-key-lee), an eastern black rhinoceros and long-time resident at Brookfield Zoo, was humanely euthanized today, May 17. Of the current population of eastern black rhinoceros, at 33 years of age, he was the oldest male living in an accredited North American zoo.

Nakili arrived at Brookfield Zoo in 1994 at the age of 4, and for nearly three decades, the pachyderm was seen by millions of guests. Over the years, Nakili was featured in zoo chats, which educated the public on interesting facts about black rhinos, but more importantly, conveyed the plight the critically endangered species faces in its native habitat of Africa (specifically in South Africa, Namibia, Zimbabwe, and Kenya). He has one living offspring named Kianga, who was born at Brookfield Zoo in 2003 and currently resides at another Association of Zoos and Aquariums (AZA) accredited zoo.

“Nakili was a favorite among the animal care staff, volunteers, and zoogoers,” said Joan Daniels, senior director of hoofed mammal care and conservation. “He had a great disposition and voluntarily participated in his training and husbandry sessions. He also participated in up-close experiences with Zoo guests, who hopefully were inspired by him to care more about his species and the natural world.”

The animal care staff fondly recalls that Nakili had the best head tilt when he wanted something and would sometimes vocalize to get your attention. And, even though he was close to 3,000 pounds, Nakili was a bit hesitant and needed extra encouragement to try or do something new. He definitely leaves a big, loveable hole in the hearts of those who cared for him.

In August 2022, Nakili was diagnosed with kidney disease, and further testing revealed his condition was progressive and non-reversible. To ensure Nakili was comfortable, the animal care and veterinary staff made several adjustments to his healthcare. Staff encouraged Nakili to drink more water, made modifications to his diet to make it easier on his kidneys, and administered medication to prevent infections. Recently, during follow-up monitoring, Nakili’s blood parameters progressed to the point that supportive care was no longer feasible, and the very difficult decision was made to euthanize him before his comfort and quality of life began declining.

The eastern black rhinoceros, is the most endangered of the three black rhinoceros subspecies—an estimated population of only 740 individuals remains in Africa. The species’ main threat continues to be poaching for its horn, which is used for medicinal and ornamental purposes. To help advance the care and population of black rhinoceros in professional care for future generations, over the years, staff was able to collect/store Nakili’s semen for genetic banking and for artificial insemination trials.

Currently, 24 AZA North American institutions have eastern black rhinoceros, including Brookfield Zoo, which has a female named Layla. The Zoo has been home to this species since 1933, a year before opening to the public.