Gorilla habitats were made possible by Holder Corporation, Katherine John Murphy Foundation and the John E. Galvin Charitable Trust. The Sanaga Overlook was funded by the Rich Foundation. Tropical plants were donated by Pike Nurseries. The Monkeys of Makokou exhibit was added to the Ford African Rain Forest in September 1990 and was expanded to include a second habitat in May 1995. These mixed species exhibits feature west African drill monkeys and mona monkeys.
Drills are primarily terrestrial and monas are mainly arboreal.
These natural characteristics make the multi-level space of the Monkeys of Makokou exhibit ideal for the two species to share. The lush habitats have a variety of tropical foliage for the animals to forage in as well as large man-made climbing trees. Close-up visitor viewing stations are located in the Sanaga Overlook aviary and on wooden decks among the trees. The drill, an endangered, forest-dwelling monkeys, is primarily terrestrial, although young drills can be seen jumping through the trees. Zoo Atlanta is one of only four zoos in the United States with a collection of drills.