Dolphins do not mate for life. A pair of dolphins typically engages in mating for a few days, but then the male goes on to mate with other females.
Dolphins mate for reasons other than reproduction, just as humans do. When food is scarce, they may not mate at all in order to focus on survival. Males fight each other for mates, colliding their bodies into each other and making sounds to warn each other off. They typically do not try to injure each other in these battles. When the fighting is over, female dolphins mate with the strongest, most dominant males. Mature dolphins reproduce once every three to six years.