In 1983 while exploring a small forest called Malundwe on the edge of the Selous Game Reserve in Tanzania, one of us (Wasser) came across two elephant skulls lying side by side. One, from a female, was big, and the other was small—it had molars just a quarter the size of the female’s and they had not yet been used enough to show any signs of wear. The poachers had first shot the young elephant, a ranger explained, so that they could draw its grieving mother close enough to kill her for her enormous tusks. This exploitation of familial ties in the sophisticated social system of elephants has been repeated thousands of times in Africa.