One of the most iconic chimpanzee figures in the world, Gregoire lived some 40 years of his life caged in solitary confinement at the Brazzaville zoo, in the Democratic Republic of Congo (DRC). He was rescued from the poorly-run zoo some 11 years ago and lived the remainder of his life at the Tchimpounga Chimpanzee Rehabilitation Center, a housing facility for orphaned animals, run by the Jane Goodall Institute. He died in his sleep on December 17th.

"Gregoire was an incredibly resilient being. Particularly for our Congolese staff, he served as a symbol for how we can all overcome adversity. There was such a gentleness about him," said Lisa Pharoah, who is the JGI Africa Program manager for West and Central Africa, in an interview for Discovery News.

"I gazed at this strange being, alone in his bleak, cement-floored cage. His pale, almost hairless skin was stretched tightly over his emaciated body so that every bone could be seen. His eyes were dull as he reached out with a thin, bony hand for a proffered morsel of food. Was this really a chimpanzee?" Jane Goodall recalls her first encounter with the chimpanzee, in 1990.

"One fond memory concerns when his sleeping quarters had to be renovated. A privacy wall that separated his nest with Clara and a second nest for two other females had to be temporarily removed. Gregoire sulked for days until the wall was erected again. He was definitely in love with Clara and needed his private time with her," shares Pharoah.

In zoos owned by people who don't know how to handle the animals, their living conditions are very harsh, and sometimes the primates are fed cigarettes and soft drinks, as tourists take no interest in the fact that the creatures are not built to eat such things. This often leads to serious diseases, which are at times fatal.

However, Gregoire was spared such a faith. He died of old age, peacefully in his sleep, after a lifetime of being caged in a concrete-floored box, on display at the Brazzaville zoo. His last years were spent in the comfort of the Tchimpounga center, where he recovered to the fullest extent possible, and he spent his time unbuttoning shirts and laughing as the caretakers tickled him.