Five million birds make this journey every year. 每年有五百万只雪雁都是这样迁徙
But for a short time each year, the long, dark winter releases its grip. 每年却总有短短的一阵日子 漫长阴暗的冬天也会放松它的钳制
but once a year they come together to have their young. 然而 每年总有一次 这些它们将会聚集在一起 繁衍后代
Those that survive their first year have the best possible start in life 那些在第一年里 存活下来的小企鹅有着最光明的前途
and the Arctic ice melts sooner each year, 北极冰层融化的时间继续提前
Each year, as the climate warms, the Arctic holds less ice. 每年的天气变暖时 北冰洋的冰就会减少
0ne out of every two cubs do not survive their first year out on the ice. 两只幼熊中往往会有一只无法在第一年存活下来
It causes the ice to advance and retreat every year. 使得冰盖面积每年都在扩大和缩小
but these are the short moments that make it possible to live in deserts the year round. 但就是这些短暂的日子使它们 得以全年在沙漠中生活