In the Arctic, any breach in the icy barrier can be a lifeline. 在北极 每一处破冰的地方都是一条生命线
These can only be reached during a brief lull in the currents. 这个地方只有在洋流暂时停歇时才能吃到
Crammed into this scrum, the birds are remarkably good-natured. But they have to be. 这些企鹅性情特别温和 这是环境使然
so the transfer must be done quickly 所以交接过程必须迅速完成
and the whales will soon be forced north as winter returns. 很快冬季又到了 这些鲸鱼将不得不前往北方
they will be forced repeatedly to make the 600-mile round trip to gather food in the ocean. 雪海燕将为觅食而不断往返海陆600英里
First, though, valuable nesting places must be defended from property thieves. 不过先得保护好来之不易的筑巢地 免得被其他鸟类占据
could bare rock be reckoned an oasis. 裸岩才会被当作一块宝地
they must be in position before the thaw starts. 企鹅们必须赶在解冻期结束前做好就位的准备
the steady roar of a billion beating locust wings will once again be replaced by nothing more than the sound of the desert wind. 无数蝗虫拍打翅膀时的喧哗将不复存在 再次取代它的只是沙漠中呼啸的风声