In the Kalahari, brief rains have given way to the dry season. 喀拉哈里沙漠短暂的雨季已被旱季替代

140. but when they become this barren, very little life can endure.
     但这里如此荒芜 极少生物能够适应
141. For many animals, the only way to survive the most hostile times
     动物们想要在最严苛的环境里活下来
142. is to keep moving.
     就必须不断迁移
143. In the Kalahari, brief rains have given way to the dry season.
     喀拉哈里沙漠短暂的雨季已被旱季替代
144. Food and water are becoming increasingly scarce.
     食物和水愈发稀缺
145. For these zebra, it's time to leave.
     这群斑马是时候离开了
146. They're setting off on the longest overland migration
     斑马的迁移距离称霸

来自《行星地球 第二季 第四集 Planet Earth S02E04 沙漠》第 143 行