0nly grass can feed plagues of these proportions. 只有草才能满足这些鸟的胃口

46. 0ne and a half billion swarm across the savannahs of Africa.
    以15亿的数量聚集在非洲的稀树大草原上
47. These are the most numerous birds on Earth.
    这些鸟是地球上数量最多的鸟
48. Some flocks are so vast that they can take five hours to pass overhead.
    这些鸟数量众多 让它们从你的头顶上飞过要花5个小时
49. 0nly grass can feed plagues of these proportions.
    只有草才能满足这些鸟的胃口
50. The ravenous hordes devour the seeds.
    饥肠辘辘的群鸟贪婪地吞食着草的种子
51. And the leaves and stems are cropped by great herds of antelope.
    而叶子和茎则被巨大的羚羊群所享受
52. The East African savannahs alone sustain nearly two million wildebeest.
    仅生活在东非稀树大草原的角马 就接近两百万（注：角马属羚羊的一种）

来自《行星地球 第一季 第七集 Planet Earth S01E07 伟大草原》第 49 行