 During a period of time between 1990 and 1998, Charles (now a well-sized Silverback male) was not interested in interacting with offspring that were not his own.And so in an effort to allow the gorilla group to meet with some of the zoo's other gorilla progeny (i.e., Barney's children), Charles spent a brief period of each day in solitude.In an effort to keep Charles contented during these intervals away from his harem, Charles was given access to large sheets of paper and non-toxic coloured paints.