In the Congo, meet a tightly bound group of western lowland gorillas led by an ancient silverback, whose chest-beating sends shockwaves more than a mile through the undergrowth; see grey Phayre's leaf-monkey mothers in Thailand battling for the privilege to babysit bright orange newborns; encounter the violent disputes of a thousand hamadryas baboons, and join chacma baboons shark egg hunting on the coast of South Africa.