In the herd most of the elephants are related. When two or more bulls join the same herd at the same time, they are likely to fight each other. They push and strain each other with their foreheads and they also wrap their trunks around earhc other like sumo wrestlers. When one of them gains the upper hand, he may gore the other, drive him away or even kill him. There is a worldwide ban on selling ivory.
Ivory is also from rhinos.