Elephants reproduce sexually, with the male mounting the female after assessing her reproductive status via chemical information in her urine. He picks her urine up with his trunk and blows it into the roof of his mouth to determine if she is receptive to the breeding process.
Receptive females have a particular walk that is recognized by the bull. She holds her head high and looks over her shoulder, and she becomes vocal, making sounds that travel long distances to help bulls locate her.
Bulls that are potential mates go through tests of strength to determine which bull gets to mate with a receptive female. Bulls will push, wrestle, ram and tusk one another until the weakest is forced to back off and allow the stronger bull to mate the female.