There's safety in numbers. 数量越多就越安全

128. But the first to do so are at the highest risk
     但第一个回来的最有可能
129. of being caught by birds of prey.
     被猛禽袭击
130. So, they wait for others to arrive.
     所以它们等候大部队一同抵达
131. There's safety in numbers.
     数量越多就越安全
132. As daylight fades, the sky fills with a staggering one million starlings.
     天光渐暗 城市上空被数百万只欧椋鸟占据
133. And then follows one of nature's great spectaculars.
     上演一场蔚然壮观的自然演出
134. How, or indeed why, they perform these marvellous aerobatics,
     它们是如何 又是为何成群起舞

来自《行星地球 第二季 第六集 Planet Earth S02E06 城市》第 131 行