On migration central, the Falkland Islands, the multitudes are busy multiplying .Female elephant seals barely escape the male's attentions long enough to give birth to pups conceived here last year. In the brief three weeks, the pup has with its mother. Its body weight will triple, as hers shrinks by a third. A bull moves in soon after the birth to impregnate her again. Each beach master on the shores may have dozens of females in his harem, and one hundred matings to complete in less than a month, all the while, having to fight off more and more challengers.