Celebrating Colo

In Current Events, Global Perspectives, Maps101 by

Colo is the first gorilla to be born in a zoo. She lived all 60 of her years at the Columbus Zoo and Aquarium in Columbus, Ohio.

Colo was the first gorilla to be born in a zoo. She lived all 60 of her years at the Columbus Zoo and Aquarium in Columbus, Ohio.

Animal lovers are mourning the loss of Colo, the first gorilla to ever be born in a zoo. The Columbus Zoo and Aquarium, where Colo lived her entire life, announced on January 17 that she had died in her sleep. It was less than a month after Colo celebrated her 60th birthday.

Colo—whose name is short for Columbus, Ohio, her city of birth—had been diagnosed with cancer in 2016, although veterinarians still do not know why she actually died. Since gorillas are only expected to live as long as 40 years in the wild, the captive-born ape had already lived 20 years longer than anyone expected.

The news of Colo’s death spread quickly. On the social-networking site Facebook, the zoo’s announcement has already been shared more than 25,000 times. People old enough to be grandparents remembered visiting baby Colo in Columbus as children. Others recalled her strong personality, her sense of humor, and her ability to connect with zoo visitors.

A Surprise Birth

In the 1950s, zoos across the United States had been trying to breed gorillas. At that time, no females had become pregnant. Discouraged, some zookeepers wondered if breeding gorillas in captivity was impossible.

At the Columbus Zoo, a young employee and veterinary student named Warren Thomas noticed what he thought were signs of mating behavior between two gorillas, Mac and Millie. The zoo’s director, afraid that Mac and Millie might hurt each other, instructed that the wild-born gorillas be kept in separate enclosures. Thomas defied those orders. He secretly placed the two gorillas together at night.

After a few weeks, the young zookeeper became convinced that Millie was pregnant. Since this could not have happened unless he disobeyed zoo orders, Thomas kept it a secret because he was afraid of losing his job. Eventually, after about eight months, Thomas told the zoo’s director.

In the 1950s, zookeepers had no idea how long a gorilla’s gestation period was. Since gorillas are closely related to humans, they guessed that Millie would carry Colo for nine months. Based on that estimate, zookeepers thought Colo would be born in early January. However, they soon learned what scientists know now—a gorilla’s gestation period is 8 ½ months, shorter than a human’s.

In December 1956, Thomas was cleaning Millie’s cage when he was surprised to find a tiny baby gorilla. Thomas distracted Millie and rushed the baby to the zoo kitchen. Colo was not breathing. Thomas tried to stimulate her breathing by slapping her back. Colo breathed a little, but stopped again. Next, Thomas gave the infant gorilla mouth-to-mouth resuscitation. After 15 minutes, Colo was breathing on her own. Thomas, who would later become director of the Los Angeles Zoo, had ensured that the first gorilla born in a zoo would survive.

Zookeepers were afraid that Millie would not know how to take care of Colo. Since Millie had been captured in west Africa while only a baby, they thought she did not have time to learn parenting skills from other gorillas. Instead, Colo was raised by humans. The zoo built a nursery, where Colo slept in a special hospital bed that was originally designed for human babies.

Colo received over one million visitors in the year after her birth. While many wanted to touch or hold Colo, only a few zookeepers were allowed to work with her. Veterinarians were afraid that Colo might become infected with human diseases.

A Long Life

In December, Colo celebrated her 60th birthday. Because she had lived at the Columbus Zoo longer than any other animal there, she was nicknamed The Queen. Colo ate a special birthday cake made with with tomatoes, her favorite food.

Colo and her human friends had much to celebrate. During her long lifetime, Colo mothered three offspring of her own. She eventually become a grandmother of 16, great-grandmother of 12, and great-great-grandmother of 3. Colo’s family members now live either at the Columbus Zoo or at other zoos around the United States.

After Colo’s birth, zookeepers learned how to better re-create gorillas’ natural conditions. As a result, more and more baby gorillas were born in zoos. Unlike Colo, most are now able to be raised by their own mothers.

“Colo touched the hearts of generations of people who came to see her and those that cared for her over her long lifetime,” Columbus Zoo president Tom Stalf said. “She was an ambassador for gorillas and inspired people to learn more about the critically endangered species and motivated them to protect gorillas in their native habitat.”


A map of Africa with areas in orange indicating where gorillas live in the wild.

A map of Africa with areas in orange indicating where gorillas live in the wild.

Gorillas in the Wild

While there are about 350 gorillas who live in zoos across the U.S., scientists estimate that there are about 150,000 to 250,000 living in the wild.

Gorillas are the closest living species to humans after chimpanzees and bonobos. The largest living primate, wild gorillas live in equatorial Africa, where they are usually found in tropical rainforests. Gorillas form family groups of usually 5-10 members. A group’s territory can be anywhere from 5 to over 30 square kilometers (3 to 19 square miles). Gorillas are mainly herbivores, spending about half of their day eating mostly stems, bamboo shoots, and fruits.

Scientists consider gorillas endangered. Some of the reasons for this designation are illegal poaching, loss of habitat, and infectious diseases. Currently, conservation groups are working to keep gorillas safe. They are making sure that the areas in which gorillas live are well protected and free of hunters.

Additional Resources

Read more about Colo at the Washington Post and the Columbus Dispatch.

Learn more about gorillas at the World Wildlife Federation.

See how people are working to help orphaned gorillas at Virunga National Park in the Democratic Republic of Congo.

See what it’s like to be a zoo veterinarian at the Smithsonian.

Images and Sources

Colo Photo: Becker1999.
Colo Photo License: Creative Commons 4.0.

Map of Africa: U.S. Central Intelligence Agency.
Map of Africa License: Public Domain.