chasing the rains. 追逐着雨水

158. To avoid starvation,
     为了抵御饥饿
159. many grassland animals follow a nomadic way of life.
     草原动物大多随水草迁徙
160. Over 2,000,000 wildebeests wander the East African savannahs
     超过两百万头牛羚奔走在东非大草原
161. chasing the rains.
     追逐着雨水
162. And they are not alone.
     不过它们并不孤单
163. Arriving on the wing,
     展翅飞来这里
164. Jackson's Widowbirds also seek fresh grass.
     杰氏巧织雀也在寻找鲜嫩的草

来自《行星地球 第二季 第五集 Planet Earth S02E05 草原》第 161 行