Leaders of the Columbus Zoo and Aquarium say the country's oldest known gorilla in captivity, and the first in the world to be born in a zoo, has died. Colo was 60.
The zoo announced Tuesday that Colo died in her sleep, less than one month after her birthday.
"Colo touched the hearts of generations of people who came to see her and those who cared for her over her long lifetime," says zoo president Tom Stalf in a press release.
She surpassed the usual life expectancy of captive gorillas by two decades. Zoo officials had recently removed a malignant tumor from her but had said she was doing well.
Stalf says Colo inspired people to learn about her species, the western lowland gorilla, and to help protect gorillas in their native habitat.
"She was the coolest animal I've ever worked with, and caring for her was the highlight of my career," said assistant curator Audra Meinelt in the release.
When Colo was born at the zoo, on Dec. 22, 1956, she made international headlines as the first gorilla born in captivity. According to the Columbus Zoo, her name - short for "Columbus" - came from a national "Name the Baby Gorilla" contest.
Not a lot was known at the time about how to properly care for gorillas, Stalf said in an interview with WOSU, so the Columbus Zoo set the standard.
"Colo was a prime example of why we matter - and I say 'we,' I mean zoos."
She eventually became a mother of three, grandmother of 16, great-grandmother of 12 and great-great-grandmother of three.
Approximately 350 western lowland gorillas live in accredited zoos, with an estimated 150,000 to 250,000 in the wild in Africa. Along with the other three types of gorillas, it is endangered due to habitat loss and poaching.