ver Cuevana 3. An Introduction to the Primates, covers 41 species of primates ranging from the 300-gram sized pygmy slow loris to the 200-kilogram sized gorilla. At least ten of these are extremely endangered species including the Zanzibar red colobus, filmed in Zanzibar, and the potto, aye-aye, and Drill, all of which occur in less than half a dozen sites in captivity.