Final answer:
Apes in the early African forests were successful due to their evolutionary adaptations for an arboreal lifestyle, such as manual dexterity, enhanced vision, and the development of tool use.
Step-by-step explanation:
What made apes successful in the lush forests of early Africa can be attributed to various evolutionary adaptations that were well-suited to an arboreal lifestyle. Apes evolved from the catarrhines in Africa about 25 million years ago, and they are distinguished from monkeys by their larger size, absence of a tail, and larger brains relative to body size. The adaptive features of apes include manual dexterity, three-dimensional vision, and limbs that were mobile, assisting them in navigating the complex forest canopy.
Additionally, the development of tool use greatly enhanced their ability to exploit available resources more efficiently. For instance, chimpanzees in Gombe's rainforest developed unique hunting techniques and tool use, such as using sticks to hunt smaller animals like red colobus monkeys and using twigs to 'fish' for termites, as observed by Jane Goodall. These tool-making and tool-using capabilities likely mirrored those of early human ancestors such as Homo habilis and Homo rudolfensis, who also made stone tools and had considerably larger brains than chimpanzees, helping them to survive on a mixed diet of plant and animal food.