The orangutan is the most highly endangered species of great ape. Orangutans are threatened by deforestation, poaching, the illegal pet trade, and the isolation and fragmen- tation of dwindling wild populations. Their conservation is impeded by certain aspects of their ecology (e. g., a rain forest habitat) and certain features of their life history (e. g., an eight-to twelve-year interbirth interval). Added to the U. S. Endangered Species List in...