英语听力：自然百科 大迁徙之繁衍生息 Need to Breed—11
时间：2018-12-26 作者：英语课 分类：自然百科2011年
英语课
Almost magically, they form a temporary nest of their own bodies. The larvae 1 and food are taken into the nursery at its centre. Tomorrow they will do the whole thing again, marching for two to three weeks to reach fresh hunting grounds, where they can set up another raiding base and reach new heights of slaughter 2.
On migration 3 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.