纪录片《我们的地球》 第365期 奇迹城市(7)（在线收听）

It's not only the abundance of food that attracts wild animals to cities.

充足的食物并不是吸引野生动物迁入城市的唯一要素。

They're usually several degrees warmer than the surrounding countryside.

城市的气温通常比郊外略高几度。

And here in Rome, in December, one animal is taking full advantage of this extra heat.

十二月的罗马，有一种动物充分利用着这丝温暖。

And it's leaving it's mark.

在城市中留下自己的印记。

In a single winter's day, ten tonnes of its droppings rain down on the city.

冬季的每一天，都有十吨粪便雨降临这座城市。

Starlings. In the evening, they come back to the warmth of the city after feeding in the neighbouring countryside.

欧椋鸟。夜晚，它们在郊外摄食后返回温暖的城市。

They must return to their roosting trees.

它们必须返回栖息地。

But the first to do so are at the highest risk of being caught by birds of prey.

但第一个回来的最有可能被猛禽袭击。

So, they wait for others to arrive. There's safety in numbers.

所以它们等候大部队一同抵达。数量越多就越安全。

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。

And then follows one of nature's great spectaculars.

上演一场蔚然壮观的自然演出。

How, or indeed why, they perform these marvellous aerobatics, we still do not fully understand.

它们是如何，又是为何成群起舞，至今我们还无法完全理解。

Eventually, en masse, they brave the descent and fill the branches of their favourite trees.

最终，它们会成群结队地降落，挑选最喜欢的树枝落脚。