Colo was rejected by her mother and was hand-raised by keepers. At the age of two, she was introduced to her future mate, Bongo, with whom she had three children. Having never gained first-hand parenting experience, Colo never raised her own children... but she did help raise her grandchildren. By the time of her death, she was a great, great grandmother, with two dozen some descendants. Some went to zoos around the country, but many remained with her in Columbus.
What makes Colo's passing truly remarkable is its testament to the changes in zoo animal welfare over the years. Prior to Colo's birth in 1956, gorillas had never been bred in captivity, and it hadn't been the long ago when they were considered virtually impossible to keep alive in the first place. Today, there are hundreds of gorillas in zoos around the world - virtually all of them zoo-borns - making them one of the most sustainable, most genetically-secure zoo populations. We no longer worry about getting them to eat, or watch them fade away from depression and disease. We now have large, vibrant family groups, and one of our greatest medical challenges is maintaining geriatric gorillas in good cardiac health; one of our main demographic challenges is managing young bachelor males.
Colo's passing doubtlessly has left a huge hole in the hearts of her many keepers and admirers. It's been touching, however, to see the community rally around them with support and fond memories of a great, great grandmother of an ape.
Colo at her 60th birthday party, courtesy of Columbus Zoo