This remarkable memoir of scientific discovery begins at the Washington Park Zoo in Portland, Oregon, where Katy Payne's revolutionary work in the field of elephant communication began. It was there that she first discovered the idea that elephants use infrasonic sounds -- sounds below the range of human hearing -- to communicate. This led Payne and her colleagues to conduct field research in Kenya, Namibia, and Zimbabwe that brought about fascinating new insights into elephants' social lives. When five of the elephant families they were studying became victims of culling, Payne changed her approach to her research as she fought valiantly to protect African elephants. Silent Thunder is a natural history rich in observation of the animal world and how humans participate in it. It is also a passionate story of Payne's own spiritual quest as she turns a keen eye on her own role in this world. On every page Payne's courage and empathy shine through, giving this unique combination of scientific journal and personal memoir an unforgettable emotional power.