Colo Born: First Gorilla Bred in Captivity

Colo was born at the Columbus Zoo and Aquarium in Ohio on December 22, 1956, becoming the first gorilla ever born in captivity. The birth was unexpected. The zoo's staff had limited experience with great ape reproduction, and the pregnancy had been difficult to confirm. Colo, a western lowland gorilla, weighed approximately 3.9 pounds at birth. Her survival was not assured. Great apes in captivity in the 1950s had extremely high infant mortality rates. Zoo veterinary science was still developing the nutrition, housing, and social conditions necessary to keep primates healthy. Colo was initially hand-raised by zoo staff, a common practice at the time that later research showed could impair social development. She thrived nonetheless. The birth proved that gorillas could survive and reproduce outside their native habitat, a finding that had immediate implications for conservation. Wild gorilla populations were already declining due to habitat destruction, poaching, and disease. If captive populations could be maintained and bred successfully, they could serve as a genetic reservoir against extinction. The Columbus Zoo became a leader in gorilla husbandry, eventually housing one of the largest family groups of western lowland gorillas in the United States. Colo herself had three offspring, sixteen grandchildren, and multiple great-grandchildren and great-great-grandchildren. She became the matriarch of a lineage that included gorillas housed at zoos across the country. Captive breeding programs for endangered gorillas expanded significantly in the decades after Colo's birth. The Association of Zoos and Aquariums established a Species Survival Plan for western lowland gorillas, coordinating breeding across institutions to maintain genetic diversity. The programs have not solved the crisis facing wild populations, where mountain gorillas remain critically endangered, but they have ensured that the species will not disappear entirely. Colo died on January 17, 2017, at the age of 60, the oldest known gorilla in the world at the time.